I always rent games first before I decide what I will buy but I forsee buying to following this year for the 360:
Bioshock, Two Worlds, Blue Dragon, Stranglehold, Halo 3, Eternal Sonata, Half-Life 2, Conan, CoD 4, Army of Two, Assassin's Creed, Quake Wars, Mass Effect
Never know if a game is going to get pushed back so that's the order of what I might buy next.