As I deal with mobiles regularly and have a device lab I get asked for advice on which mobile to buy. This is my advice for buying a phone as at January 2013.
Whatever you get you'll need a SIM, I'm not really aware that any network is particularly better than any other but make sure you get a decent amount of data bundled - ideally all you can eat. Don't be tempted by "free" phones, the phone companies make a good deal of their money on these "free" phones by charging a much higher monthly rate and locking you into a 24 month contract. Get a SIM only deal and buy a SIM free phone - this will be cheaper in the long run.
If you wanted an iPhone you would have bought one already so I'll rule that out.
I'll also rule out BlackBerry, the main reasons for choosing a BlackBerry are their excellent keyboards and BBM and, again, if you wanted one then you would have bought one.
Windows Phone 8 is a good operating system and the Nokia hardware is very nice but there just aren't enough apps out there to make it a practical choice. As nearly everything is cloud based these days there is no longer any advantage in having the same operating system on your phone and computer and that certainly goes for Windows 8 as far as I have seen.
If you're still reading then you want an Android phone. There are a lot of Android phones to choose from so we need to start narrowing down the field. You can find a good number of cheap Android phones and, having used a few for device testing, they feel cheap - small screens that scratch easily, cheap plastic casings that feel flimsy, low battery life, slow processors, small memory and limited application availability. At this point (January 2013) there is no point in buying an Android 2.3 (Gingerbread) phone - it's been obsolete for some time and your phone will almost certainly never receive an update. You should buy a phone that comes out of the box with Android 4 - don't buy a phone that claims to be upgradeable to Android 4 as it will be old sock by now and you run the risk of the update not being made available by the manufacturer.
We're now down to Android 4 phones which limits the choices to a manageable number. The leading contender is the Google Nexus 4, it's a really nice device, it's not too expensive and you get a Google reference device that is likely to receive operating system updates for the foreseeable future. However, there are two big drawbacks to this phone:
- Stock is very limited and they are consequently hard to obtain.
- They have no expandable storage in the form of microSD card slots.
With even the largest option being 16GB this lack of expandable storage might be a deal breaker for you if you want to carry round large amounts of media. If storage space is important to you then I suggest you get a Samsung Galaxy S III. It's a similar spec to the Nexus 4 but has a microSD card slot and is readily available.
If the Galaxy S III is too pricey for you - it's almost as much as an iPhone 5 - then the Samsung Galaxy S III mini is the next best bet. As the name suggests, it's smaller than the S III and the Nexus but still has a respectable spec and will take microSD memory cards.
Hope that helps.