Left 4 Dead is probably one of the better co-op games that's sporting a zombie theme. I mean who doesn't want to play a game with a bunch of other people where the key to winning is working together? However that will only happen when these kinds of players aren't around ruining everything for you.

The Achievement Hunter

Have you ever wondered why that player in your team is only using a pistol in expert mode? Or why they don't want to be healed during the course of the campaign even though they're already at 1 hp and is slowing down your team big time? They're after one thing...to get that achievement in their Steam account at all cost. Don't get me wrong, getting achievements is certainly something to look forward too later in the game but they have their place and time.

The Bad Shot

I honestly don't think the survivors look a lot like the infecteds at all. However, for some unknown reason even if there's no infected around you're gonna get shot and incapacitated by this type of teammate. It's not that they're doing it in purpose...some just well, they just can't identify a f*ckng Tank from Zoey. Now pair this player with someone trying to get the Safety First achievement...

The Exploiter

Have you ever seen someone in a weird spot like let's say the ledge during the Crane event in Dead Air when you're in Survival Mode? That's because they want to glitch the entire round making pretty much every single type of infected fall through the buildings. Since there's no way for them to climb up and get you (Valve please fix this), all you need to do in order to get a Gold is have patience. Just look at your leaderboard? Seriously, who has the time to play an entire Survival Mode round for more than 5 hours? You've got to be kidding me.

The Rusher

This player will usually go first before anyone else during the entire campaign and will either end up doing two things - Getting incapacitated while you guys are far away and eventually die or come back running to you guys with a bunch of infecteds. Does Co-op ring a bell or something?

Sometimes we change our environment just to keep the atmosphere of the game alive and kicking i.e. turning off the lights so it's kinda scary when playing games such as Left 4 Dead. This player however will take it to the extreme and will usually play his character the way they think the character should be played...Zoey, stay in the middle because you're the girl in our group and I'd like to protect you with my shotgun.

The Professional

You're a f*cking nub, wtf are you doing?! F*ck this, this is why I don't play campaigns with nubs. I only play 4v4 in InsertLeagueNameHere. That's right, this player is a professional gamer. That's how they see themselves even though they sound like a 10 year old in-game. They're perfect, they don't make any mistakes and if they did by any chance make a mistake, it was you that lead them to make that mistake. It is never their fault...it's always you, you suck big time son.