I got a Nexus S a couple months back for £200 sim free. Shoved Ice Cream Sandwich on it and it's great! Absolutely love it! It doesn't 'really' do anything that my last 3 phones (all nokias) couldn't do, but it just does it much simpler and more effectively than nokia managed..
Never been one for iPhones.. I've played with a coupel but I just don't get them.. Find them far to restrictive and locked down for my liking and TBH as a device, not exactly groundbraking. Even when teh first iPhone came out I was able to compare it against the N95 I had for a few months previously , and apart from lack of touch screen the N95 could do EVERYTHING! the iphone coudl do and quite a bit more!.. With the iPhone your buying a name, not a quality device IMHO.. But each to their own.. It's whatever is right for you.. I'd just get far too frustrated with one..