PixelJunk Monsters Deluxe & Everyday Shooter are amazing games from small indie studios.
LittleBigPlanet, Ratchet and Clank and Daxter are some must plays from Sony.
GTA Vice City Stories, MGS Peace Walker, Star Wars Battlefront Renegade Squadron are fun games from third parties.
Honourable mention for The Sims 2, not for being good. But for being interesting

Stop Skeletons from Fighting has some amazing docs and just released another for Mighty Number 9 that was really good