ehh. it's more than five, but..
(in no particular order)
Exclusives:
Metal Gear Solid 4
Warhawk
Uncharted: Drake's Fortune
Super Stardust HD
Gran Turismo 5: Prologue
Pixeljunk Monsters
Ratchet and Clank Future: Tools of Destruction
Resistance: Fall of Man
Folklore
Multiplat:
Call of Duty 4
Grand Theft Auto IV
Devil May Cry 4
Soul Caliber IV
Near Future:
LittleBigPlanet
Motorstorm: Pacific Rift
Resistance 2
Not trying to be a fanboy. Of course, it's hard when you own the best console eve... dang it