Best smartphones to look forward to in 2015

With the pace of smartphone evolution moving so fast, there's always something waiting in the wings. No sooner have you spied the latest handset, then there's anticipation of something else, the next big thing to envy.

We've rounded up the best smartphones for 2015, those we consider to be the best across all platforms, and we've regularly updated that list as the smartphone world has evolved.

You can find those in our Best smartphones 2015: The best phones available to buy today feature.

Here we're looking at those phones that haven't yet launched, those we know are coming, or are anticipated. As we run towards Mobile World Congress 2015, we enter the busiest time of the year for smartphone launches.

We'll be updating this list on a regular basis, with those device rumours we think are credible and exciting, and devices just announced but yet to hit the shelves.

HTC One M9

The HTC One M9 is an evolution of the M8 in may ways. It sticks to a similar design, but adds refinement at every level. We loved the M8 design and the M9 just makes it tighter, sharper and more premium than ever before. 

Importantly it's better in the hand than the M8, with a more defined profile so it sits well in the hand. It also hasn't grown from 2014. In fact, it's slightly smaller, but still offers a 5-inch full HD display, which is lovely.

Internally there's plenty of power with the latest Qualcomm Snapdragon 810 chipset and 3GB of RAM. There's been a switch around in the cameras too, with 20-megapixels on the rear and the 4-megapixel UltraPixel on the front, which should address some of the criticisms of the previous handset.

There's been some fun elemments added to Sense 7, but it pretty much sticks to the experience that was there before. It sits nicely on top of Android 5.0 and it's slick and fast from what we've seen so far.

Some might say that the HTC One hasn't changed enough from the previous device and in some ways that's true. If you're happy with your M8, this isn't a complete reinvention. But this is a phone that carries a lot of luxury with it.

HTC One M9 will be available on 31 March, costing £579.99.

READ MORE HTC One M9: The devil is in the details (hands-on)

Samsung Galaxy S6

Samsung didn't have the success it wanted with the SGS5, so it's a total overhaul with the Galaxy S6 (and its parter in crime, the S6 edge). 

Unveiled at Samsung Unpacked at Mobile World Congress 2015, the SGS6 certainly feels premium: it's all machined metal and Gorilla Glass 4 both front and back. That's the kind of finish we've been calling for for a couple of years and here, finally, Samsung has really pulled it off. However, it does mean a non-removable battery in this latest model.

Behind the front glass is a 5.1-inch Quad HD Super AMOLED screen that, in typical Samsung style, looks great. It's all punchy colour and contrast across the 2560 x 1440 resolution panel, and thanks to slender edge bezel the phone feels an ideal size, avoiding the wide phablet territory of some competitors, such as the LG G3.

Interestingly Samsung has ditched Qualcomm as its processor partner, instead opting for the self-made Exynos chipset comprising a 64-bit octa-core setup (pairing quad-core 1.5GHz and quad-core 2.1GHz units with 3GB DDR4 RAM).

Now that's all a lot of numbers, but it's an important change: with the SGS5 we felt there was a little something lacking in terms of user interface fluidity, and having used the SGS6, which runs on Android Lollipop out of the box, it felt slicker. How well it holds up after extended use we'll have to wait and see when we review the phone in full.

Claims of the best smartphone camera money can buy were rife at the Unpacked conference too, the Korean giant particularly keen to peck away at Apple and the iPhone 6. Combining 16-megapixels on the front with an f/1.9 lens and optical image stabilisation the latest software works a charm.

Overall we think Samsung has done a cracking job with the Galaxy S6 - but it's the S6 edge (below) that really pushes things that much further.

READ MORE Samsung Galaxy S6 preview: Giving the people what they want

Samsung Galaxy S6 edge

The Samsung Galaxy S6 edge takes the curved concept of the Note 4 and wraps it around a wholly different idea. In essence it's a design piece; a darn good-looking slice of phone design at that, with the left and right screen edges curving away in an almost bezel-free format.

The functionality, however, isn't there as it is in the Note Edge. Sure, the S6 edge has a favourite callers feature, accessed from a click-and-drag of the side edge, but it's not the full-on secondary app listing.

And we don't have a problem with that, because the S6 edge is all about Samsung showing off what it can do in design terms. Curved glass, a metal body, and all the top specs pulled directly from the "standard" S6 squeezed into a phone like no other.

Our moans about it are fairly minor: it feels too light for a 5.1-inch phone (that might sound like a bonkers complaint, but it feels like a stiff breeze would pinch this phone from the hand); the various finishes seem capable of sucking in the world's supply of grubby fingerprints (it's a total magent for them); and like the SGS6 there's no waterproofing or removeable battery.

The only question now is whether this curved screen version of the S6 will cost the earth. We hope not because, well, just look at it. It's lush.

READ MORE Samsung Galaxy S6 edge: Bye bye bezel

Microsoft Lumia 640 XL

This 5.7-inch Lumia gives you a big screen Windows Phone experience, but really isn't that expensive. That's not uncommon for Windows devices recently, with the Lumia 640 XL available from €189, which sounds like a bargain.

It isn't the most powerful Windows Phone available, but there's some intesting details, like the 13-megapixel camera on the rear with Zeiss optics. There's also a 5-megapixel camera on the front, making it more appealing than the regular Lumia 640 it launched alongside.

In the hand it feels pretty good and although big, we think it's just about managable. The design is typical of Microsoft Devices in the post-Nokia era, and although it's plastic, it feel solid enough.

The 640 XL was launched alongside plenty of talk about Windows 10, but it's running Windows Phone 8.1 with Lumia Denim. It was slick and fast enough in our demo, but there's no telling what the real-world performance will be like.

READ MORE Microsoft Lumia 640 XL: Big brute packs in Zeiss lens (hands-on)

LG G4

The LG G4 could arrive with the smallest bezel on any screen yet, if the prototype displays shown off by LG are anything to go by. We're expecting a screen around 5.5-inches, probably with a 2K resolution, like the G3, with a very slight curve, as recent images have revealed.

LG has said in an interview that the LG G4 will have a radically different design to the G3. There's some discussion around whether it will use the Qualcomm Snapdragon 810 chipset, or use its own hardware that is in development, but having seen SD810 in the G Flex 2, we suspect the G4 will be the same.

LG has also confirmed that there's work to be done around the user interface, with a desire to clean things up for the user. LG has confirmed that a new user interface will be revealed before the LG G4 is announced.

There have been previous reports that the G3 will be given a year in the market before the update is announced, which would give us a date of late May or early June for the LG G4 release.

READ MORE LG G4 what to expect

HTC One E9

We're sure that HTC has a number of devices lined up, one of which has recently surfaced as the HTC One E9. The name is a little odd, as the plastic body would suggest that it's actually the Desire E9 - following the Desire E8 we saw last year.

However. It's said to be a 5.5-inch device with a Quad HD display and MediaTek innards, rather than Qualcomm. This is likely to be a cost saving measure.

There's said to be a 20-megapixel camera on the rear and either a 13-megapixel camera on the front (like Desire Eye) or UltraPixel (like One M9).

It should be running Sense 7.0 and Android 5.0 Lollipop, but we suspect this will be a phone heading for China and not for wider international release.

READ MORE HTC One E9 surfaces

Sony Xperia Z4

Of all the devices forthcoming, least is known about Sony's plans for the Sony Xperia Z4. Sony didn't have an event at MWC 2015, as it skipped out of its previous hardware cycle.

There isn't a huge amount to go on, but it's suggested that we'll see a slightly new face on the Z4 with a repositioning of the front-facing speakers, and perhaps a step up to Quad HD resolution for the display. It's been suggested that the casing will be exactly the same, rather than there being a redesign.

Rumours suggest an updated camera too, but still with 20.7-megapixels and optical image stabilisation on the back. A boosted front camera is likely too, as is Android 5.0 Lollipop.

There's no date on the Sony Xperia Z4 release at the moment, but with MWC out of the way, we suspect Sony will let things settle, before announcing it's next superphone later in 2015.

READ MORE Sony Xperia Z4 rumours

HTC One M9 Plus

The rumour of the HTC One M9 Plus has come up a couple of times. It was suggested that the HTC One M9 Plus would appear alongside the HTC One M9 at MWC, but that wasn't the case.

So that might mean that we're still expecting this other device to surface. There's talk of a 5.5-inch display, so it's not much bigger than the 5-inches of the HTC One M9.

Images have appearing of a device with Duo Camera, so it might be that HTC is going to stick to that concept for this second device. We'd expect the internal hardware to be the same - Qualcomm Snapdragon 810, 3GB RAM - but using the Duo Camera would be an interesting move following its lukewarm reception in 2014.

It's also been suggested that the HTC One M9 Plus will be limited release, perhaps destined for Asia only.

READ MORE HTC One M9 Plus news and rumours

Sony Xperia Z4 Compact and Ultra

The Sony Xperia Z4 Compact is apparently going to arrive with 3GB of RAM, a 20.7-megapixel camera, 32GB storage, and a 4.7-inch screen with 1080p resolution. You can also expect a 3,000mAh battery, Cat 9 LTE, wireless charging and IP68 water and dust proofing.

The Sony Xperia Z4 Ultra should arrive with a 6.44-inch display with a QHD resolution. It should also come with 3GB of RAM but a smaller 16-megapixel camera and larger 4,000mAh battery. Unlike previous versions of the Ultra this model should also come with a stylus.

Sony has made a start on the Z4 family with a new 10-inch tablet, but there's been no sign of any phones just yet.

READ MORE Sony Xperia Z4 news

Huawei Ascend P8

Huawei has confirmed that the Ascend P8 is coming and that it will be launched at a global event in London on 15 April.

Aside from pinning a date on the launch of this new handset, Huawei has said little else about it and there's been no leaks to speak of either. However, given that the focus has been on thin and light, we'd expect that to continue.

Huawei has also used its own hardware, so it will probably come with the latest generation of HiSilicon chipset and with Huawei being one of the largest providers of telecommunication infrastructure, you can bet it will be well-specced for 4G LTE support too.

Huawei's big consumer play has often been the camera performance, so we'd expect something like a 13-megapixel rear and 8-megapixel front camera.

Whether there will be an Arsenal FC special edition remains to be seen.

READ MORE Huawei Ascend P8 rumours and news

Asus ZenFone 2

Asus has been one of the first companies to launch a new device in 2015. The Asus ZenFone 2 was launched at CES 2015.

Asus has stuck with Intel for the hardware, with an Intel Atom Z3580 paired with 4GB of RAM, which should make for a really powerful handset.

There's a 5.5-inch display, with 1920 x 1080 pixel resolution as well as a 13-megapixel camera on the rear. Asus is making great claims about this camera, saying it will offer low light performance like you haven't seen before. We'll be the judge of that.

The ZenFone 2 has rear volume controls, like the LG G3, and it ships with Android 5.0 Lollipop skinned with Asus' Zen UI.

Fortunately, despite some premium specs, the ZenFone 2 comes with the $199 starting price tag. We're yet to hear exactly where it will be on sale, however.

READ MORE Asus ZenFone 2 preview

Asus ZenFone Zoom

We didn't see this one coming, until Asus teased "optical zoom" in an oh-so-obvious way. But Asus now has a smartphone with optical zoom that was announced at CES 2015.

There aren't many cameras with optical zoom around and the ZenFone Zoom is a world away from the Samsung Galaxy K Zoom. Samsung's model is more like a camera, however, with 10x optical zoom and a 20MP sensor, along with Xenon flash. The Asus, however, is fairly slimline, cramming the 3x optical zoom 13MP camera into a body that's still pretty slim.

To assist that camera is laser autofocusing, but we're yet to see if this all fuses together nicely, or if it's a mish-mash experience.

Elsewhere the Asus ZenFone Zoom has a 5.5-inch display and will launch with Android 5.0 Lollipop, along with Zen UI. It's still some way off, however, with no word on when it might be available.

READ MORE Asus ZenFone Zoom eyes-on

Microsoft Lumia 1020 replacement/RM-1052

This rumour is a little on the loose side, but a newly-leaked image has appeared showing a Lumia model with a big camera bump on the rear. The Lumia 1020 was a mobile photography star, but has never been replaced and all of Microsoft's recent devices have been at the budget end of the spectrum.

There's a chance that you're looking at a new high-end PureView model, known as the RM-1052, but equally it could be a prototype of the cancelled Nokia McLaren.

But it's nice to dream that Microsoft Devices will fill the high-end with a 5-inch Windows 10 device with a great PureView camera.

We're not convinced by the bodywork, the metal and plastic fusion doesn't look like a finished consumer device, but it could be the birth of a new photography star for 2015.

Stephen Elop announced at MWC that a new flagship would be coming later in the year, so Windows 10 will have itself a new device to play on.

READ MORE Microsoft Devices news and reviews

Google Project Ara

Created by Motorola, and now shifted over to Google after the sale of Motorola to Lenovo, Project Ara isn't due to early 2015 but is essentially an exoskeleton that allows users to modify what parts they want. That way someone that wants to spend the bulk of their budget on the camera, but doesn't need as much storage, can chose to upgrade that way. Perhaps one person will skip NFC in favour of faster 802.11ac Wi-Fi, for example.

There should also be third party components on offer that will allow for competitive pricing as well as new types of parts - like sensors. A person with diabetes may want a blood sugar sensor where another may not.

Users can also looks forward to different textured options that they can 3D print off at home themselves. The speed this phone can develop at, without costing us as much, is very exciting indeed.

READ MORE Google's Project Ara modular smartphone: Everything you need to know