After a bit of research, we finally ended up buying a 48" Smart Full HD 3D. It's brilliant, and the smart controller is cooler than I expected too. We tried the 3D glasses, which are a good gimmick but I'm not sure we will actually use them.
With the new TV going in the lounge, it meant the other rooms received 'new to them' TVs as well. Cue lots of shuffling around today.