Dallinor on 17 May 2009
Pixeljunk Monsters ia great first PSN game to get. It's an entertaining tower defense game with co-op. It's not too expensive either.
I think there is still a discount on R&C:Quest For Booty in the EU store, so that would be another option if you like platforming games.
Burn Zombie Burn! is a mindless zombie shooter with co-op, if you just want something you can play in small doses.
