I don't rage quit, but there is one thing that makes me really mad. When you play someone (this is online of course) and you can tell that they think they are good when they are obviously not. You beat them and they pick your character, to show you how to play it. And they are completely playing the character wrong, doing retard combos (which they think are awesome), not doing any of the little tricks that every character has, but somehow manages to beat you because they get away with bullshit due to online lag and then they probably teabag you or something stupid. I want to fucking kill someone when this happens.