I play PlanetSide 2 and Arma 2 regularly with organized groups online, and both require a great deal of communication to succeed. The good think about the two communities I'm in, they don't take themselves too seriously, and when you screw up, you usually don't get anything more rude than "Oh, man, that went badly... Now you know not to do that again, right?" I also play Eve Online, which I've found to be very friendly and mature, for the most part; willing to have a random chat or offer suggestions or assistance to newer players.
Of course, I tend to avoid games with notoriously rude or immature playerbases, like League of Legends and Call of Duty.
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It takes a village to raise an idiot, but it only takes one idiot to raze a village.