What are some awesome Xbox live games like Borderlands?

Definitely check out Red Dead Redemption. It has a great campaign (not sure if it is co-op) and a great free roam online that you can play with up to i believe 16 people in a group (possy is what it is called in the game). The game should be fairly priced since it is a fairly old game that didn't have a huge market. Also, check out fallout 3 because that game is awesome.