Commander Assassin, here's some more recommendations [i'm heavily biased towards open-world games]
- inFamous - PS3 exclusive, good-sized city to wire-surf around in, and solid cover shooting.
- Just Cause 2 - Literally the biggest world in a console game, full of crap to blow up and cheesetastic voice acting. Grapplechuting.
- Assassin's Creed - A lot of people don't like this for the repetitive nature of the story, but it's three absolutely gorgeous cities to climb and one of the better video game stories.
- Assassin's Creed II - Adds considerably improved gameplay and a ton of new mechanics to the original, drops some of the story's intelligence, and wraps it in Italian flair. Get this if you have any interest at all in Assassin's Creed: Brotherhood later this year.
- Batman: Arkham Asylum - Probably the best superhero game ever.
- Mercenaries 2: World in Flames - Cheesier than JC2 and pretty buggy, but it's almost completely destructible, full of vehicles, and you can get it on the cheap.