Shadow of the Colossus: Excellent. It's longer than Ico, with more action, and just as beautiful and intriguing.
Ratchet: Deadlocked: Disappointing. They kind of phoned it in on this installment, I think. The story was virtually non-existent. I didn't find the weapons to be as entertaining. Maybe I'm just getting tired of this series. I haven't tried the multiplayer support.
SSX On Tour: Satisfying. The snowboarding gameplay is largely the same as in SSX3 (except for the ubertrick system), but on a new set of runs. I haven't tried skiing yet.
Guitar Hero: Satisfying. Almost excellent. The guitar controller makes it easy for non-video-gamers to get into this game. However, for the hardcore gamer this game falls short of Dance Dance Revolution. DDR has an extensive practice mode, and GH desperately needs a similar mode.