Crackdown

Nevermind the fact that the game comes with an invitation to the Halo 3 Multiplayer Beta — this game is worth the cash even without that highly-desired extra. In Crackdown ($60), you play as a genetically-altered "agent," a member of the police grown to deal with the seemingly unending crime problem in your city. As your abilities grow, you'll be able to jump from rooftop to rooftop, hurl cars at bad guys, and generally play bad-ass superhero as you roam freely (GTA-style) around your city making the streets safe once again. Go forth, and kick ass.