Left 4 Dead.
This just might be the best co-op game I’ve ever played. 4 players versus insane zombies, running from building to building, fucking shit up proper. From the Shacknews Review:
It’s actually very easy to quantify just how replayable Left 4 Dead is, in the same way that one can identify an infectious disease.
Because that’s what playing Left 4 Dead for the first time feels like–the beginning of a terrible affliction. We played the game for two straight days at Valve, only occasionally surfacing for a gasp of fresh snacks. We played so much Left 4 Dead that it made us all physically ill. We came home thoroughly infected, bed-ridden and moaning like the undead.
And the most common phrase going around our chat channel? “I wish I could play more right now.”
It really is that much fun.
If anyone needs me, I’ll be on Xbox Live.