Iv got about 250 quid, and wanting a new computer. so, ps3 xbox or wii?

Don't bother with the xbox360, it costs more to do the online stuff, and thats the only reason people say it is a good thing. A PS3 is your best bet, because it has excellent graphics, easy gameplay, it can play Blu-ray/dvd, and you can store tonnes of videos, games, pictures, music, etc on it. The wii is only good for parties.