I’ve watched a lot of people playing Left 4 Dead and Left 4 Dead 2 and they seem to make a lot of damn mistakes, n00b to advanced gamers alike. Some of the things I’ve seen would piss me off if I was playing with them.

1. Running and shooting at a Jockey on one of the survivors back just to run up on him to melee him. I’ve seen this countless times, instead of shooting and missing because you can’t aim and you know you’re just going to go up to it and melee, just go up to it and melee the jockey instead of wasting bullets.
2. Shooting at an already dead infected and special infected. You saw the infected or special infected go down for the count, why are you still shooting at it? Its not going to get back up. Waste those wonderful bullets on that hunter that has incapped your friend that’s mauling him/her right next to you.
3. Splitting up because you want to find the Witch or chase down a Charger. I’ve seen this happen numerous times and it didn’t turn out well most of the time. They kill the Charger or Witch then try and high-tail it back with the other survivors just to get snatched by a Smoker or mauled by a Hunter. Now the other survivors have to come all the way back and save you. What happens then is the possibility of it being another horde because you the idiot who wanted to be Rambo was in that area for too long.
4. Setting traps because you think its fun to make other gamers miserable. I just hope this never happens to me but I’ve seen other players open and close the safe door rapidly so the other survivors cannot get inside after that one idiotic player wanted to set off a car alarm and provoke a horde. I’ve seen people in versus push a garbage dumpster down the sewer opening so the survivors cannot get up the ladder. I’ve also seen in versus where gamers would push a generator in front of the elevator in the finale of No Mercy so when the elevator opens up and the survivors that want to evacuate the premises, they can’t. It might be fun and hilarious the first few times but leave that retarded bullshit with your friends that play the game, not random players that just want to play.
5. Trying to help a survivor up knowing there’s a horde beating you half to death. People defeat the reason of helping someone up. I know you’re trying to help and all but just let me die or kill the horde, the smoker, the hunter, and the tank off first. You could have a full bar of health but you want to help me up while there’s a tank hot on your ass. Its call paying attention to the health bar if that person you’re trying to help up is that close to death when they’re incapped and a horde comes; kill the horde and see the outcome.
6. Running ahead and leaving the other survivors because you’re impatient. This is not NASCAR, yes the finish line is the safe house but the point in the game is to survive. No I don’t mean stick around and wait for an ass kicking but if there’s someone trying to fight a horde off which in fact happens all of the time, don’t just say “screw this” and Speedy Gonzales your ass to the safe house. The other players will hate you forever. If you’re illiterate or dyslexic and you can’t understand “stick together to survive” then sucks for you.
7. Looking for short cuts and glitches in the game just to end up dying anyway. First of all, looking for an easy way out in a game just means you’re an idiot and lazy. Look for easier ways to get out shit in real life, stop taking the fun out of the game because you think its cool to waste your time leaving the survivors because you found a glitch and or a short cut only you got down to a Science.
8. Camping because you think its the right thing to do in this type of situation. People can still camp in Left 4 Dead 2 believe it or not. Others are killing zombies trying to live and here one person is off in the corner some where camping or hiding. You know he or she is not shooting anything because you can see the outline. He or she is  just waiting for it to be over. Then without warning [it never is one] a hunter incapacitates he or she and he can’t get immediate help because the others are still killing a horde or dying themselves. So now he or she is pissed and rage quits. Camping is only good in a group not solo. Even then camping isn’t good, camping is just waiting for a Chuck Norris type ass kicking to come your way.
9. Using a health pack then taking another leaving other survivors vulnerable. There is one for everyone, no need to get greedy because 9 times out of 10 you’re going to wish you gave that guy who was on his last leg that health pack. Especially when the odds are against you; meaning two of the other survivors was killed and its only you and the guy you neglected to help. Remember, sharing is caring!
10. Getting on the mic screaming at another player that they’re “n00bs“. Come on! If you want to play with gamers you like, find some friends or make some. People will cringe and get this feeling of wanting to falcon punch your ass when they see your gamertag or your steam name when you’re in a lobby waiting to play after a while. No one likes a dumb ass with a mic. I’m pretty sure those that’s always bitching about others being n00bs were once n00bs themselves.
11. Seeing a tank then running all the way back to the beginning of the map. I don’t how many times I’ve seen this happen. They see a tank, then run all the way back to the safe house or a room with a door that they just so happened to find that a tank cannot open. What is the point? Just shoot the got damned thing! Oh if you haven’t noticed, throwing a Molotov Cocktail just pisses it off more and some has said that the tank moves faster once its on fire. I don’t know how much of that is true but its better than running away or into something worse.
12. Replenishing ammo, shooting zombies then coming all the way back to get more ammo. I get sick of that, people be at times so far away from that pile of ammo the next pile would be right next to them but they go all the way back to get more ammo. If you aim right your bullets would be of good use and you wouldn’t have to worry about wasting them to the point you have low self-esteem about it.
13. Healing someone during a crescendo. Who the hell waits til then to want to heal someone? Those few precious seconds between crescendo’s is when you’re supposed to do that. Not when there is a car being launched at your torso or when a hunter is playing finger paint with your insides.