First, there is a server browser:
http://www.left4dead411.com/news/2008/11/server-browser-available/Secondly: I'm really like versus, campaign not so much. The problem with versus is, I hardly find anybody decent in this game.

Infected attacking the survivors one by one. (Yeah, a single hunter is really hard to fight off if you stand together!) Survivors don't realize a hunter has just jumped me although I'm right next to all 3, so they even got pushed back by the jump. Boomers playing as if they don't respawn when they die. Infected not attacking from the very beginning, because it's a hard to attack place, so rather they spawn half the level ahead, giving the survivors a free ride. Hunters running (running, not jumping!) up to the survivors and simply attacking them with their claws. Smokers jumping down in front of the survivors in the no-mercy-turbine-room, trying to strangle one of the survivors (yeah, right!). Survivors falling back all the time, survivors falling back at places where you can't get back to, making a free lunch for a hunter. Survivors running into witch in a way where you can't get to them without getting hit. Survivors startling the witch when you're telling them to stay back and getting your moltov ready. I could go on

Oh and of course: bug-using is nothing to be ashamed of, your teammates expect it from you!

Also, playing survivor against a good team is physically exhausting for me, making it hard to play a full evening.
And of course, only having 2 out of 4 campaigns is pretty disappointing.
[/rant]