Nintendo: Zelda, Pokemon, Xenoblade.
Sony: God of War, Ratchet and Clank, Jak and Daxter, Uncharted, The Last of US, Resistance, Demon souls, Heavy rain/Beyond, Sly Cooper, InFamous, LBP, Tearaway. Team Ico games.
Microsoft: Gears of War, Halo, Fable, and even DR3 looks awesome, I just haven't played it yet. (Just remembered Dead rising isn't exclusive, forgot I have DR2 for PS3)