Halo 3 and modern warefare 2 for me
I think the key really is in limiting how much you put in the game honestly, cause from each of those titles things expanded but at the same time there's only so much you can do with one thing and I also think multiplayer and single player games are more effective when they create an experience for the player in a certain time frame. By that I mean you basically play the game and after years have gone by you remenisce instead of trying to get that feeling back with the latest edition