Many great ones listed, I'll try a few nobody mentioned:
Crush - Very original and fun puzzle game
Disgaea: Afternoon of Darkness - Great RPG, fun story and combat
Dungeon Siege: Throne of Agony - Good RPG, similar to Diablo
Hot Shots Golf: Open Tee 2 - Fun and addictive game, very similar to Mario Golf
Burnout Legends - Another great Burnout game, fast paced arcade gameplay