Traded in Forza 3 (very VERY disappointed with that - Forza 2 was brilliant, for this they upped the graphics a tad, a few new cars/tracks and made the gameplay worse) and bought Bad Company 2.
Singleplayer is very good, not quite MW1/2 level, but fun to play, love the distructable environment.
Apparently the multiplayer is what makes it, played a little, seems very good, but the lag on it is unreal. Had to give up after 20mins or so because it was unplayable. Hopefully i just caught it at a bad time/joined a bad game or something.