Xbox:
Rock Band Best. Game. Evar. I love getting the band together to jam, and we recently went to visit my bro and his band to have a battle, which we won (their coming down for a rematch next month)
Halo 3 On this bandwagon a little late, but it's fun. I can even frag my 13 year old nephew at it, which blows me away.
The Orange Box Meant to get Half Life 2 for the PC, never did. Meant to download Portal from Steam, never did. Playing them both now and they're a blast.
NHL 08 Best hockey game in years. My Habs aren't doing too bad in the dynasty I've started.
Wii:
Super Mario Galaxy Funnest platformer I've played, probably ever (not a fan of platformers).
PC:
The Witcher Gameplay is not the super best, but the story is pretty good, keeps me wanting to come back for more.