Borderlands
http://borderlands-wiki.com/ (by THEGAMENET)
Borderlands is a science fiction FPS (first-person shooter) and RPG (role-playing game) developed by Gearbox Software for Windows, Xbox 360 and PlayStation 3.
In the game, four co-op players enter the harsh frontier planet Pandora in search of an Alien vault legend. Think post-apocalyptic Earth in the Fallout theme.
Using Epic's Unreal 3 engine, Borderlands is one of the best-looking FTP games produced to date.