I'd say it really depends on what grinds your gears. I'd say a tie with the younger population of Minecraft and the younger population, or rather, the less mature side, of popular FPS games. The thing with minecraft is you have people who can't type a sentence without complaining. I try to remain considerate, but it seems a good minority of the community act like they need to be pampered. You send them out in the wilderness for a week in the game, and they'll be dead the first day. then they'll go "this sever is gai!!1!"
With FPS games, it seems the worst of people are those who are very...alpha. I don't need to say much, as I'm sure you know what I'm talking about. just defies logic that such people are acting all "holier-than-thou" over a video game...