Best smartphones 2015: iPhone 6S, OnePlus X and Nexus 6P

We count down the most exciting mobiles hitting or already on the shelves this year

With 2015's end fast approaching, we've seen a wealth of top-end smartphones over the past months. These have ranged from camera focused-handsets from Korean heavyweight LG to affordable flagships from Taiwanese Asus.

In fact the year has been so full of phone news, some buyers have justifiably struggled to stay on top of which handsets have been released and which are on the horizon.

Here to help, we've created a definitive list detailing 2015's current best smartphones.

OnePlus X

This is a device of firsts for OnePlus. It's the firm's first mid-range smartphone, its first AMOLED display and its first handset to slip below the £200 mark, with the glass-built 'Onyx' model costing a very agreeable £199.

There's nothing middling about the OnePlus X's performance, though - it includes an old but surprisingly spry Qualcomm Snapdragon 801 quad-core processor along with 3GB of RAM, resulting in benchmark scores that are almost on par with the LG G4. The 5in FHD display is bright, crisp and colourful enough for any task, too.

Unlike a lot of other cheap smartphones, the OnePlus X also does an excellent job of disguising its affordability with utterly gorgeous glass and ceramic bodywork, with classy touches like the ridged metallic band running around the edge. It won't outpace the iPhone 6S, but looks just as slick.

iPhone 6S

Apple's regular refreshes shouldn't surprise anyone, but the newly-launched iPhone 6S is hardly lacking in intriguing features. Chief among these is the 3D Touch display, which can detect finger presses of varying force - this allows for a neat new way of controlling apps, as a slight touch can perform certain actions from the home screen without having to actually open the app itself.

Under the hood, there's a new A9 processor, which Apple says is 70 percent faster the the iPhone 6's A8 chip in CPU tasks and 90 percent faster in GPU tasks. Other hardware improvements include a 13MP iSight rear camera, 5MP front camera and a new aluminium body to help prevent the bending issues that plagued the iPhone 6.

The iPhone 6S also comes pre-loaded with iOS 9, an essential upgrade over iOS 8 with its six-digit passcode support, handwriting features in Notes and a battery-saving Low Power mode. This last addition might prove particularly handy, as the iPhone 6S' battery has dropped to 1,810mAH - though Apple claims the more efficient A9 chip will still ensure a lifespan of up to 14 hours of talk time.

Best smartphones 2015: iPhone 6S, OnePlus X and Nexus 6P

We count down the most exciting mobiles hitting or already on the shelves this year

Silent Circle Blackphone 2

Few smartphones are as laser-focused on security as the Blackphone 2. While the original, call-encrypting Blackphone was designed mainly for privacy-minded consumers, the new model aims to play more of an enterprise role, updating its Android-based Silent OS software to include support for Android for Work.

Silent OS also allows users to create separate, secure sandboxes for work, personal and social data, and fine-tune app permissions through a dedicated 'Security Center' - all in addition to the headline feature of fully encrypted voice, video and text messaging. For blocking government snooping or thwarting industrial espionage, the Blackphone 2 might well be the best around.

High-end hardware means it's no slouch, either. A quad-core Qualcomm Snapdragon 615 chip with 3GB of RAM offers solid processing power, while the big 5.5in display, 13MP camera and 32GB internal storage drive are on par with most good consumer handsets.

Nexus 6P

Google is marking the launch of its latest OS, Android 6.0 Marshmallow, with a duo of new Nexus devices: the Nexus 6P phablet and the smaller, cheaper Nexus 5X.

Both are crammed with high-end features, like all-metal unibodies, rear-mounted fingerprint sensors and USB-C ports, but the 5.7in Nexus 6P undoubtedly has more premium appeal.

That massive screen runs at an ultra-crisp 2560x1440 resolution, and the inclusion of an octa-core Qualcomm Snapdragon 810 processor - with 3GB of RAM - should ensure competitive flagship-grade performance. The 12.3MP rear camera, far from being a downgrade on the Nexus 6's 13MP sensor, also possesses the rare quality of being able to capture 4K video.

Starting at £449 for 32GB of storage, the Nexus 6P is also considerably cheaper than its phablet rivals, the iPhone 6S Plus and the Samsung Galaxy S6 Edge+. That price, of course, also includes an unskinned copy of the latest and greatest Android version, well before it rolls out to other manufacturers' models.

Motorola Moto G 2015

The 3rd-gen Moto G continues the series' tradition of offering solid mid-range specs and performance at an entry-level price.

Starting at a mere £159, or £179 if you want to add customised colours via the Moto Maker site, the new Moto G is equipped with a 64-bit, 1.2GHz quad-core Snapdragon 410 processor and up to 2GB of RAM. This allows it to keep pace even with demanding 3D apps, while its benchmark scores easily beat other budget competitors like the Honor Holly.

What's more, it runs a clean, bloat-free Android 5.1 Lollipop - an extreme rarity among sub-£200 handsets. The lack of a custom skin should also help ensure the Moto G receives OS updates much sooner after they're released.

The sharp 13MP rear camera, which can capture 1080p video, and 5MP front camera are also great inclusions for the price. It's durable, too, being waterproofed to the IPX7 standard. In other words, it will survive submersion in depths of up to one metre for 30 minutes; or, more realistically, an accidental dunk in a puddle.

Best smartphones 2015: iPhone 6S, OnePlus X and Nexus 6P

We count down the most exciting mobiles hitting or already on the shelves this year

Asus ZenFone 2
Asus unveiled its first Android 5.0 Lollipop smartphone, the ZenFone 2, at CES 2015. While the use of Lollipop, which more upgrades to Android than can easily be counted, is pretty awesome, Asus has done a stellar job loading the ZenFone 2 with a wealth of top end hardware.

Chief of these are the ZenFone 2's 13MP rear camera with an f/2.0 wide-aperture lens, Optical Image Stabilsation (OIS) and a 5MP PixelMaster front camera.

PixelMaster is a custom technology designed to improve the ZenFone's imaging performance by adjusting the pixel size and image-processing algorithms to "improve low light performance by 400 percent" and "enhance noise reduction and colour contrast by up to 200 percent".

The ZenFone 2 will also feature an upgraded camera application that allows the manual adjustment of settings like ISO and shutter speed.

The combination of imaging tech and software mean the ZenFone 2 may be one of the best options for avid photographers.

Nexus 5X

The Nexus 5X is more than just the Nexus 6P's little brother - it's a solid upper-mid range smartphone in its own right, capable of swift performance thanks to its Qualcomm Snapdragon 808 processor and 2GB of RAM and brimming with features that belie its sub-£400 price, such as its 4K video camera and integrated fingerprint sensor.

It also has the distinction of being the cheapest Android 6.0 Marshmallow device around, making it a great entry point for users who might otherwise be waiting a long time for their current handset to update - if it ever will.

The new OS brings with it built-in support for the Nexus 5X's fingerprint sensor and USB-C port, as well as attractive improvements like a more privacy-friendly app permissions model and Doze, a battery saving mode which uses the device's motion sensor to sense when it's been left alone for a while, thus sending it into a frugal low-power state.

Best smartphones 2015: iPhone 6S, OnePlus X and Nexus 6P

We count down the most exciting mobiles hitting or already on the shelves this year

HTC One M9
The HTC One M9 may not be the most original smartphone to arrive in 2015, however, as we noted in our full review, it does still tick all the necessary boxes.

Featuring a similar metal chassis to the M8 that wraps around its front Gorilla Glass display and twin 'boom sound' speakers the One M9 comes loaded with some impressive internal components.

These include an upgraded 20.7MP, 5376x3752 pixel with autofocus, dual-LED (dual tone) flash camera that pushes the M8's 4MP pixel to the front of the M9 and super fast octa-core Qualcomm Snapdragon 810 processor.

We're particularly pleased to see the removal of Ultrapixel from the rear camera unit. Ultrapixel is a custom technology debuted on the One M7 designed to improve quality by creating larger pixels that can capture 300 percent more light than those of a regular camera sensor.

In the past we haven't been impressed with the technology and have found that photos taken on Ultrapixel cameras aren't as crisp or vibrant as those taken on competing top-end smartphones, particularly when blown up

Sony Xperia Z3+

Sony impressed in 2014 with its Xperia Z3, with many, including us here at V3, feeling it was one of the year's best smartphones.

Aware it's found a winning formula, Sony chose not to radically rethink its design strategy for its 2015 flagship, the Xperia Z3+.

Featuring a close to identical design to the Xperia Z3, the only visual changes to the Xperia Z3+ are the micro-USB port's move from the top left to the bottom of the phone and the removal of the cap cover and magnetic charging pins.

However, under the hood Sony has made a number of key software and hardware changes to the Xperia Z3+.

One of the biggest is the use of Qualcomm's octa-core Snapdragon 810 processor, which promises to radically improve the Xperia Z3+'s performance.

Sony's also loaded the Xperia Z3+ with an impressive 20.7MP camera with Exmor RS rear camera and super sharp 5.2in Full HD 1080p 1920x1080 pixels IPS display with Sony's custom Triluminos for mobile and X-Reality for Mobile technologies.

Add to this the benefits of Google's stellar Android Lollipop mobile operating system and we can't help by think the Xperia Z3+ has repeated its predecessor's success.

Best smartphones 2015: iPhone 6S, OnePlus X and Nexus 6P

We count down the most exciting mobiles hitting or already on the shelves this year

Nokia Lumia 930
Microsoft made a big deal about Windows Phone 8.1, listing it as the first "enterprise-ready" version of its mobile OS, when it first arrived in the UK.

Having thoroughly tested Windows Phone 8.1 during our full review, we can understand why. Featuring advanced security and productivity features, such as a new Word Flow Keyboard, and mobile device-management support plus all the inherently great mobile applications seen on previous Windows Phone versions, Windows Phone 8.1 is truly fit for business.

As a result it's no surprise the Lumia 930 - which, as well as running on Windows Phone 8.1 also features top-end hardware, including the Finnish firm's hallowed PureView imaging technology - is one of the best phones currently available.

Apple iPhone 6 Plus
Apple claimed for years that users didn't want big-screen smartphones and there was no need for a handset to have a display any bigger than 4inches. However, given the popularity of big screens in other ecosystems, such as Android and Windows Phone, it's become increasingly clear this is a false hypothesis.

Finally aware of this, Apple this year unveiled its first-ever phablet, the iPhone 6 Plus. Featuring a sizeable 1920x1080, 401ppi Retina HD display the iPhone 6 Plus is the first ever handset to bring all the inherent benefits of iOS 8 to the big screen.

As an added incentive Apple's actually optimised its latest iOS 8 mobile operating system to work better on the iPhone 6 Plus's display. For example, the iPhone 6 Plus's Messaging and Mail apps have a special two-tier horizontal user interface and separate keyboard with special keys for actions such as cut and paste.

Best smartphones 2015: iPhone 6S, OnePlus X and Nexus 6P

We count down the most exciting mobiles hitting or already on the shelves this year

Samsung Galaxy S6

The Galaxy S6 was one of the most anticipated Android handsets of all time.

Following on from the Galaxy S5, a handset that failed to meet Samsung's sales projections, the Galaxy S6 is designed to recement the Korean firm's lead in the Android market.

As a part of this Samsung quite literally went back to the drawing board designing the Galaxy S6 and created what in many people's minds is its most interesting handset to date.

Featuring a reworked design that combines metal and Gorilla Glass Samsung claims the Galaxy S6 is its most robust smartphone to date.

Specifically Samsung claims the metal makes the Galaxy S6 50 percent stronger than other high-end smartphones and "unlike other smartphones, will not bend".

Within the reworked frame Samsung's also loaded the Galaxy S6 with some top end, never before seen components.

These include a "one of a kind" 14nm, 64-bit octa-core processor, super sharp 5.1in Quad HD 2560x1440 577ppi screen and high end 16MP, F-1.9 with Real Time HDR and Optical Image Stabilisation rear camera.

Add to this the inherent benefits of the Google's Android 5.0 Lollipop operating system, combined with Samsung's own Knox security service and we can't help but think the Galaxy S6 is one of 2015's best smartphones.

You can also read our Galaxy S6 versus HTC One M9 review.

LG G4

Unveiled at the end of April, the LG G4 is one of the most exciting handsets to arrive in the UK this year.

V3 has thoroughly tested the LG G4 and we're impressed with the device, which achieved a four star rating in our review.

The G4 may not be a major overhaul in the same way as the Samsung Galaxy S6 or Apple iPhone 6, and the hexa-core processor may not match other top-end handsets on paper.

However, a great display, top-end rear camera and atypical design make the LG G4 one of the best smartphones available, according to the findings of our review.

This is especially true when you consider its £500 price tag, which makes it close to £100 cheaper than most other high-end smartphones.

The G4 features the same rear-facing physical keys as the LG G3, and comes with a "natural arc" that LG claims will make it sit comfortably in the hand.

Add to this the G4's 5.5in 2560x1440 IPS Quantum display, six-core Qualcomm Snapdragon 808 processor and Android 5.0 Lollipop operating system and it's clear the LG G4 is a contender for smartphone of the year.