I know that most people here are PC gamers, but for those few xbox 360 gamers out there I wanted to suggest that people check out Red Dead Redemption. I don't know what it is about westerns, but I have a certain affinity for them. I've had this about a week or so and have played it way too much already. Being about to form up a posse in MP and then go raid some bandit camps is too much fun. It's 360/PS3 only and unfortunately you can play across platforms (man, I wish they would fix that at some point). If you have a 360 and RDR, then add me to your friends list so we can play some MP.
Note added: This game isn't for kids. My boys are not allowed to play it. Why? Lots of bad words (BC2esc) and some sexual topics. You have been warned.
Free Roam (Multiplayer Trailer)