Mass Effect 2... but at the same time maybe not. The game comes out at the end of January and we have no idea what other games could come out during the year. Zelda Wii? Star Fox Wii? F-Zero Wii?
I'd rather wait until E3 at least.
Random game thought :
Why is Bionic Commando Rearmed 2 getting so much hate? We finally get a real game and they're not even satisfied... I'm starting to hate the gaming community so f****** much...