no story, no problem
The campaign is great is campaign map is different from one another in its own way, for example one might be in the sewers and another will be in the woods. It was a little short but that doesn't matter. The most impressive thing about left 4 dead is how each playthrough in the game is different. Sometimes you'll find zombies swarming on you every 10 seconds, other times you'll find areas completely deserted. This makes it have great replay value. All people will soon find that this mode is much more fun with friends then your slow aimbot AI friends.
Were the game is really at its best is within versus mode. You fight in teams of 4 on 4 one team being the survivors and the other fighting as the infected try to stop them from reaching their destination. It may possibly be even more fun to play as the infected than the survivors. The one downside is the respawn time as the infected is much too long considering you normally die with one blow with the shotgun. Another pointer is that you don't choose your special infected you won't find 4 hunters at once.
Survival is another fun challenging mode great with friends but sour with the AI. All in all this is a near perfect zombie game that will leave you hungry for brains.
P.S. I like potatoes