Gamers who constantly bully other (usual younger or less experienced) gamers via chat and by killing them repeatedly. These gamers harass others and usually swear and insult endlessly over the game chat. Annoying. Usual kids or teenagers.
Lagger- that shouldn't be on the list. What do they do? They just want to play the game, despite not having the best hardware and/or connection. They don't DELIBERATELY irritate anyone.
Prepubescent children- People underestimate their maturity. I've seen a lot more immature 17 year old gamers than I've seen immature 8 year old gamers, even on games that have a larger number of 8 year olds.
Basement dweller- Pretty much neutral on that one. Again, they are just video game enthusiasts- who are we to insult them?
Camper- On some Multiplayer games, campers can't exist. Probably one of the worst people on the list, but it's often fun to go to their hiding places and blast them all to smithereens.
Trickshotter- Meh. I don't care for them, but a worse category is someone who brags about stuff that's pretty weak. Trickshotter deserves a place on this list, but there are some worse.
Horrible player that makes excuses- sometimes I do that, and they genuinely are things that happen. Like once, my brother walked in half way through a racing game loudly. I felt free to blame that when I lost by a tiny amount later. If they genuinely failed and are blaming random things around them, that's bad, but at least you know that you deserved that win, despite what they say.
Someone who can't shut up- this is the one I chose. I find it really irritating when every few seconds something new pops up on screen that is not important, especially considering the appalling English used. As a grammar freak, this breaks my concentration- I have a much higher win rate when there isn't someone like that on chat than my win rate when there is. Also, when people get sick of them and ask them to stop, usually politely I might add, they start insulting everyone around them. But as the people he insult have far better arguments and grammar, all (s)he convinces people of is that (s)he is a drunk..... 3 year old..... Rock. Not to insult drunk 3 year old rocks.
Guys camping with a LMG with a target finder annoy me the most. Even when you sneak in to kill them, they have a shotgun as a back up, so you're pretty much screwed. Only way to win is to be a moron like them, and do the same to the other team.