Left 4 Dead question and a general which game is best in your opinion for the 360?

[siska]

I want to know about the Versus mode in Left 4 Dead; can you play it offline just with bots? Or do you have to play it online? And I've been looking at some games and rented Gears of War 2 and have been considering Unreal Tournament 3 (What's the campaign like?), Left 4 Dead, Fable 2, or pretty much any shooter (I have fallout 3 already and farcry 2) Any suggestions? Or information on Left 4 Dead.