Vegas, Puzzle World, Hot Brain, SBK-07 and Xiaolin Showdown.
Rainbow Six Vegas
Time was, people used to scoff that you couldn't do first-person shooters on a console. TimeSplitters and Halo disproved that notion, no matter what some musty old PC obsessives would have you believe, and so now we move to a new battlefield: you can't do first-person shooters on a handheld.
I'd love to say that the PSP version of Ubisoft's latest Tom Clancy terrorist slayathon is the one to help tip the balance of popular opinion but, sadly, it's more than a little poopy. Even though the game is set in Vegas, the paltry spread of levels all take place in anonymous villas and caves, so the opening animation of heavily armed mayhem reflected in a roulette wheel proves cheekily misleading. Good start.