From the PlanetXbox360.com feature list:
"When you mention the throng of co-op games available for Xbox 360, you usually get giddy with excitement. After all, a great assortment of these games let you work alongside friends towards a common goal, whether it’s blowing the Locust Horde to hell or having a field day jamming out with friends. But let’s say, just for the sake of argument, you didn’t have access to an online connection. Are you out of luck when it comes to playing multiplayer games with your friends? Hardly. There are a number of games for the Xbox 360 that let you compete with (or work alongside) others without the need of an internet connection. So, just to keep you on the safe side, we’ve got our favorite local co-op/multiplayer games. Pick up those four controllers (or more, if the game supports it) and have yourself a party."