Must get:!
Gears of war
F.E.A.R
Oblivion
Halo 3(Ships 11/01/07)
Dead or Alive 4(one of the best fighting game/best online fighting game)
Enchanted Arms(Really good RPG)
Huxley(Ships 01/01/07)

Optional:
DOA Xtreme 2(only if you want to see some sexy females)
Phantasy Star Universe(only if you like pso, or want to play an mmorpg with a monthly fee)
Sonic the Hedgehog(only if you like sonic)