So, here we are. The big phones of 2013 (well, the first half of it at least – we've still got the iPhone 5S / iPhone 6 to land at some point) have all landed and you're probably wondering which is best.
Well, it's not as easy as usual, as we have three stand-out contenders for the throne of best smartphone. Luckily for you fancy people we've spent weeks with all three and have put together this in-depth test to show where the HTC One, Samsung Galaxy S4 and Sony Xperia Z have strength and weakness.
So, onto the battle… it's not going to be pretty, but at the end you'll be able to know which is the best smartphone on the market right now as it comes stumbling through the smoke and into the daylight.
Having killed the other two, in case that wasn't clear.

Design

Design-wise, there's a big disparity between all three devices on show here, as each has a different take on how the smartphone should look. The Samsung Galaxy S4 is using a similar construction to its predecessor, which may be polycarbonate but looks and feels rather cheap in the hand. It weighs practically nothing, which is a real plus point, but there's no doubting that it doesn't justify the cash in overall feel.

HTC One vs Samsung Galaxy S4
It does have one design win though: while maintaining the same footprint as the S3, the Galaxy S4 now has a 5-inch screen that pushes much closer to the edge of the handset, which gives a much more immersive feel.
That said, the Sony Xperia Z is really struggling to show it's worth the cash as well, with a very plastic shell and one that sounds really cheap when tapped on the back - it's got a very hollow ring to it and doesn't scream that you've bought a phone worth the best part of £500.
However there's a fairly good reason for the cheap-feeling design: the Xperia Z is both waterproof and dustproof, with seals around each port to stop water and other nasty stuff affecting the use of your new smartphone.

The most impressive on test is the HTC One, with its full aluminium shell. It's something of a masterpiece in terms of design, with it feeling more like a sculpture than a smartphone. It also took years of work to understand how to make something out of aluminium to this degree while still letting you make calls and stuff.
Sure, aluminium isn't as durable as plastic, but hold all three in your hand and we challenge you not to fall a little in love with the HTC One.

Ease of use

The Sony Xperia Z and the HTC One both share a common operating system in the shape of Android 4.1. It's an excellent OS, but one that's bettered by the Galaxy S4's Android 4.2 offering. Both are called Jelly Bean, but the latter does come with a larger amount of bells and whistles.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
But we're not talking about the features here - it's how easy each phone is to use. From that perspective the Samsung Galaxy S4 is in third place. That's not to criticise it too much, as it's an excellent OS and one that really rewards the user the more you dig into it.
But if you're after an operating system that allows you to pick it up and just get to grips with all the functionality, the other two are streets ahead.
The Sony Xperia Z isn't too far removed from core Android, and by that we mean the layout and extra features are both pretty simplistic, sticking relatively close to what Google wanted when it created the OS. And when things get more technical, the phone is fluid and intuitive, automatically giving you information on your music and movies from the web which creates a really nice effect.
But we love the fact there's a superb effort on the HTC One to make the smartphone more accessible, from the reduction in apps on the grid (which HTC says is the direct result of research into finding out what barriers consumers are finding to smartphone purchase, although you can extend this) to the more helpful tutorial screens that litter the phone when you turn it on.
The blend of simplicity and power here is what makes us feel that handing our grandmother the HTC One will be the least difficult experience... providing she doesn't go into BlinkFeed, that is.

Performance

There are two ways of looking at performance: either real life use or by trotting out a number of benchmarks to see how strong a phone is when it comes to raw grunt.
In both cases the Sony Xperia Z comes last - its attempts to show that its quad-core processor can mix it with the big boys showed there's still a little way to go in terms of making a smartphone that just works without flaw.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
In terms of benchmarking, the Z is far behind its peers, seemingly the result of Sony finding its feet as a full smartphone brand. It also has a few bugs in the software causing it to pause and flicker on a couple of apps – it's nothing major but it's also not a problem we're seeing in the other devices.
In terms of performance, there's very little to choose between the HTC One and the Samsung Galaxy S4. The latter nudges it in the Antutu Android test, but it's honours even in the browser benchmarking tests, showing that there's not much to choose here if you're going to raw power.
Neither will falter even under heavy use, which is great news for the smartphone users of the world.
It's just a shame that Samsung didn't unleash the octa-core version of its phone onto the UK and US – apparently that thing is shredding up benchmark charts the world over…

Value for money

When it comes to value for money, it's hard to argue the case for any of these phones, as each is at the top end of the scale when you're thinking about the monthly fee to fork over.
However, there is a slight disparity between the three, and the Samsung Galaxy S4 comes at the wrong end of it. It's available for £580 SIM free, where the other two can be nabbed for £530 and £490 respectively. This is less of an issue when it comes to contracts, where the S4 is £1 more expensive per month, and carries a higher upfront cost to boot.

http://www.techradar.com/reviews/pc-mac/software/operating-systems/android-jelly-bean-1087230/review
None of the three really cost over the odds though - £35 is the rough marker we'd expect to be paying per month for a top end smartphone (if you want a decent whack of minutes and internet allowance) and all three manage to sit in that area.
But there's no doubt that the Galaxy S4 offers less value for money than the other two, simply because it has arguably the lowest design values and the highest price. It's got some decent internals, but there's a worry that the South Korean brand is getting a little too much like Apple in its high-end price strategy.
It's a hard choice between the HTC One and Xperia Z in the value for money stakes: the Z is cheaper, but comes with half the memory. That said, you can add a memory card into the Sony version to expand the memory, and for less than the £40 difference between the costs.
The HTC One could be considered the best economically, as it has the best feature set and design combination while not taking the mickey when it comes to price either – but the lower price and high feature set of the Xperia Z mean it should get the value for money title.

Features

The feature set on most of today's smartphones are immense - there's very little you can't get information on already, and with the smorgasbord of apps, it gets a little bit frightening.
All three of the devices on test here have a lot of attempted innovation on board, although some are more impressive than others. Let's start with the Sony Xperia Z, a phone that promises a lot from the revamped brand.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
Our favourite features on the phone from the outset are the Smart Connect and the Xperia Link. These two are clever as they take away all those unnecessary key presses the blight our daily lives, inching us ever closer to fat beings that sit on floating chairs all day long.
Smart Connect lets you set an 'event', be it plugging in the charger, entering a location or even a time of day, and sets the phone to do something automatically. So whether that's open the alarm, turn on music or just going into silent mode, it feels very intuitive.
Xperia Link allows you to use the phone's internet connection to other devices. That's a familiar feature, but you can remotely set it to function from another device, without having to dig it out of the pocket on a commute. Nice.
The Samsung Galaxy S4 is probably the most feature-rich of the three, with a whole heap of 'innovation' on board. Be it scrolling with your eyes, waving your hand over the phone to move through photos or internet pages or just keeping track of your peepers to maintain screen brightness, there's a lot going on here.
The latter feature aside, a relic from the Galaxy S3, none of it works though. That's not completely true: it works, but is utterly pointless. Scrolling with your head or tilting is a very poor relation to just using your finger, and the same goes with Air Gestures. When forced, we can think of reasons to use these (having no hands, for example) but really it just shows that Samsung needs to go back to the drawing board when flinging new ideas on the consumer market.
Or at least making them infallibly amazing, and not bettered by incumbent methods.
If Samsung was looking for an approach to ape, we'd heartily recommend the HTC way of doing things. The One has loads of filler features: be it the UltraPixel camera that can take low light pictures, the BoomSound microphones that prevent distortion when recording at high volume, or the simple user interface, there's a lot here to love.
HTC has gone for the physical when it comes to innovation, and for the most part it completely shines through, making it a really solid purchase, while the other two scrabble around to make their ideas work.

Camera

The camera on all three phones is excellent - but there's a big difference between the three. Well, not so much the Sony or the Samsung option, as both are rocking a 13MP sensor, but when it comes to the HTC One, you'll have to make do with a 4MP option.
The Samsung camera is the most powerful of the three, as while it packs the same resolution as the Xperia Z, it manages to come up trumps when trying to frame the perfect shot. You can get almost flawless macro shots instantly and without having to coax the phone to take them; it also has a wide range of features that are presented in a really easy to use interface.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
The Samsung Galaxy S4
The Sony Xperia Z is also a contender here, as it builds on a rich cameraphone heritage to take some rather lovely pictures. The Intelligent Auto mode is strong, and often came up with the best quality of picture during our testing of random scene types. Be it indoor or out, we were often surprised and impressed at the richness of colour on offer, as well as the overall detail.

Sony Xperia Z
The Sony Xperia Z
The HTC One takes things in a different direction, and that's not necessarily a bad thing. The 4MP UltraPixel camera is probably one that most of you are familiar with, but here's a quick overview: a 4MP sensor can have bigger pixels, which let it more light for an overall brighter photo - excellent in lower lights where you don't want a flash.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
The HTC One
It can also capture and process them more quickly, as there's less information to chug through, and you can take some really clear and in focus shots. The downside is the resolution is noticeably lower and while the subject your aiming at is generally clear, the rest of the picture can be noisy and a little fuzzy.
Another new feature we like: the HTC One lets you capture Zoes, which are 3.6-second clips instead of a photo. These not only automatically make highlight reels of your night out or holiday, but also let you do really cool things like sequence shot and object removal much more easily than with the Samsung Galaxy S4.
Samsung promises excellent low-light snaps from the S4 as well, but it simply cannot take on the might of the HTC One when trying to get the photo in even near-darkness.
The HTC One is best for day to day shooting, which is really important on a cameraphone, but it really depends on what you're intending to use your phone for. The good news? If you're after a decent cameraphone, you're going to get something more than decent from any of the options here.

CPU / RAM

All three phones are pretty similar here: the One, Z and S4 all pack 2GB of RAM to help power things along, but as you can see from the benchmarking graphs, Sony is struggling to keep up with the other two.
Its results are surprising, given that it's packing a 1.5GHz Krait chip from Qualcomm that's also supplemented by an Adreno 320 GPU (which is also present in the other two). However, it performs markedly worse than the competition, which you can put down to the lower clock speed.
HTC made the decision to move to Qualcomm Krait, and despite being slower than the Galaxy S4 (coming in at 1.7GHz clockspeed) manages to match it blow for blow in the benchmarking tests. It also performs nigh-on flawlessly even in the heavy lifting.
The Samsung Galaxy S4 is much the same in terms of interface, but raises the bar to 1.9GHz in speed terms. As we mentioned, this has very little effect when it comes to benchmarks, but it does impress given the battery life isn't impacted massively.
We're going to give this one to Samsung for just edging it in terms of pure specs. Sure, it matters what you do with it, but it seems the South Korean brand has managed to be a bit kinder on the battery. We just wish that we were allowed to buy that octa-core version…

Screen

This is such an important part of the smartphone experience, and all three offer something different in display terms, although Full HD resolution has been packed into each handset.
We'll start with the Sony Xperia Z, which has the poorest screen on test. A standard TFT LCD, it's certainly crisp but really suffers when viewed from any other angle than straight-on. We would have thought this wouldn't be an issue, but the amount of times we were really surprised at the washed-out screen when looking at it from the side was much higher than anticipated.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z

The HTC One has the brightest screen, but the Galaxy S4 has a much more balanced tone with the Super AMOLED (which has been set to the most neutral colour mode) when viewed normally. The Sony Xperia Z has the best clarity, but that comes at a price as it's also the most noisy.
However, it's interesting to note that at the higher magnification, the S4 has the most jagged edges and obvious pixels, showing the HTC One has a very high-class screen.
The HTC One also uses LCD technology, but opts for Super LCD3 as a display and as a result performs so much better. It helps that its peak brightness is much higher (although beware of this munching your battery), but it also packs such an improved contrast ratio as well - far more than we've come to expect from an LCD screen.
(For the uninitiated, the contrast ratio is the distance between the full black part of the screen and the white elements - the further apart this is, the better the display, especially when used in high brightness areas).
The Samsung Galaxy S4 uses a Super AMOLED Full HD screen, which is a whole new type of technology. This allows an almost infinite contrast ratio, as the black parts of the screen are true black and not slightly grey while masking the backlight needed to light up the screen.
The difference between the One and S4 is negligible to some people, but when it comes to watching video or browsing the internet, we can't help but love the S4. It's got a lower peak brightness than the One, but doesn't need to be as bright as the better contrast ratio makes everything look sharper and clearer.
Its screen packs a very slight greenish tinge when viewed at full brightness though, meaning when placed side by side with the One it can look like some sort of washing powder ad. But that hue does make watching the screen a little easier on the eyes, which is far more important.
We challenge anyone not to be a little bit wowed when looking at the 5-inch Full HD screen crammed into such a small device, but if you prefer things brighter, then the One is for you. The S4 is better on all around performance though; we simply cannot stop watching all manner of things on that glorious AMOLED display.

Media

We know this is verging on a broken record, but once again all three phones pack a real media punch, and for different reasons. The Sony Xperia Z draws on some really powerful heritage in this space, using things like the Bravia Engine to improve the quality of movies.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
HTC has drawn in Beats audio enhancement and combined it with its new BoomSound technology to create an even better sound, and the Samsung Galaxy S4 has the best sound quality of the lot - plus it's got the most intelligent audio and video monitoring of the lot to ensure consistency.
The HTC One is the only device currently sold with a 32GB internal capacity, which makes the price impressive. However, it lacks a storage slot for increasing the memory, which is rather irritating as it can fill up with music, video and photos rather quickly.
The Sony and Samsung offerings both are offered in 16GB versions (although the latter will be available in a 64GB flavour) and come with the memory card slot we love, which makes them very easy to upgrade.
When it comes to out and out video performance, you'll be able to tell that we like the Samsung the most if you check out the screen section above - and on top of that it's got the most options for altering the quality of the video on screen. It also has the best video player offered by default (HTC doesn't even HAVE one) and will auto-play thumbnails of the clips in your library too.
Sony offers Gracenote identification for each movie, so when the info is downloaded you'll get official information about your films if you've nabbed them from a hard drive. It also uses the aforementioned Mobile Bravia Engine 2, which really does well to improve the performance of an otherwise uninspiring screen.
And the HTC One is good when it comes to watching films without headphones, as the Boomsound speakers offer a really crisp and punchy sound for a mobile phone.
On the audio front they're all excellent, with intuitive players, sound enhancement and a rich UI that makes it easy to find your content. The Galaxy S4 only lets itself down in this area by having the weakest music player widget, but that's a really small criticism compared to the might of the playback.
Although it's horrendously tight, the Samsung Galaxy S4 just feels so much more professional in the media stakes and builds on a nascent heritage at making mobile media manageable, meaning we find ourselves reaching for that one when wanting a marathon music session.

Battery

What's one of the most important things a smartphone can do? Not to lose all its power when doing nothing in the pocket.
It's very difficult to talk about how strong a phone's battery is, as so many people use it for different things. Any phone is going to crumble in hours if you do a lot of video streaming, and using the camera loads (with all the processing going on) will similarly chuck the juice out the battery door.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
In our tests, we found that the HTC One and the Xperia Z both did the best at the video playback test, with both of these only losing 19% when playing back a 90-minute video.
The Galaxy S4 only dropped another 2%, with 79% juice left at the end, so it's not a big problem at all. And it should be noted that we brightness corrected the test, so all had the same lumen output during the video playback. However, the Galaxy S4 uses algorithms to boost the brightness and colour reproduction up when playing back video, and with the same output managed a much, much better picture.
So like for like, the S4 lost the test, but if you want to enjoy your movie then you'll need more brightness from the One and Xperia Z, and battery life will suffer accordingly.
In real life usage, we found the Xperia Z to be the poorest. We played video and took photos on all three, then playing music and browsing the internet intermittently. Even with Stamina Mode turned on (which is supposed to save battery life when the phone is not in use by switching off mobile data and stopping apps syncing) it still only lasted until 7PM.
The HTC One managed to get to nearly 9PM, but the Samsung Galaxy S4 kept right on chugging until nearly midnight, when it still had around 10% of its juice left.
It's worth noting that all of these phones have excellent sleep modes though – if you're planning on only having them for email, a quick bit of app or internet browsing and perhaps some music on the commute, you could get up to two days' use between charges, which is a real step forward for battery management.

Verdict

So - down to the main reason you'll have come here: which is the best mobile phone on the market right now and why?

Sony Xperia Z

The Sony Xperia Z is a darn good phone, there's no two ways about it. There's a really crisp screen, the waterproof shell, a strong effort at making usable media apps and a quad core processor under the hood.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
It does need an improvement when it comes to battery life though, as we noted some real issues there. It's also got one of the most unwieldy designs, with a blocky exterior only helped by the fact it's able to withstand life's knocks and lumps.

Samsung Galaxy S4

This is Samsung's best phone ever, without a doubt. We were worried that it would be something a little iterative from the S3, and while you can argue that's the case for the design, what's underneath is a new animal.
The Full HD Super AMOLED screen is fantastic, it's breathtakingly good at doing things like browsing the web and playing media, and it comes with a bunch of new ideas to play with.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
The problem is those new ideas simply don't work. For all the hard work making it a decent phone, the moves from the S3 really comprise of a slightly more solid design, an uprated camera, a boosted processor and a better screen. It's still a really nifty set of changes, but it's not enough for us to recommend it over the HTC One.

HTC One

The One is a masterpiece from HTC. The build quality is superb, and enshrines a really top-notch screen that really takes the fight to Samsung. BoomSound and Ultrapixels are novel and useful concepts, and the Zoe functionality brings a twist to cameraphone use, if not being the most needed of things on a phone.

HTC One vs Samsung Galaxy S4 vs Sony Xperia Z
It may run into some issues when it comes to the onboard storage, and heavy use will push the battery a little hard, but this is a smartphone that fuses art with power.
Winner: HTC One
The HTC One is the winner nobody would have seen coming last year, but we've got to take our hats off to the Taiwanese brand for making something so usable and well designed.
The Samsung Galaxy S4 is a powerhouse, and one that we like to use day to day a lot, but it's definitely all evolution without much in the way of revolution in smartphone terms.
The Sony Xperia Z feels like a great step forward for the electronics giant, if not the handset to scale the smartphone peak just yet. It's chock-full of great ideas, but needs some design and interface work before it can be considered a true great.
So if you're short on time and have to make a snap decision, go for the HTC One. We promise you won't regret it.