Basically I went through nearly every game for xbox 360 in the xbox catalog on Left 4 Dead HAS to only be 2 player offline, because of the split screen. There's Splitscreen coop games dying?.
2 players via split - screen, 2- 4 players over System Link or Xbox LIVE; Up to 8 players in Versus mode, where some players control.
For Xbox 360 on the Xbox 360, a GameFAQs message board topic titled " Recommend me some 4 player split screen games!". 13 Greatest Couch Co-Op Games