The absolute one thing that annoys me is people loudly chewing gum in the lines. Not like normal chewing, but LOUD, squishing, pure determination to chew! Drives me up the wall!!!
Another one, that has been mentioned a few times is people that randomly stop. There has been a few times when I've been walking about and suddenly the person just stops, out of the blue!
Oh, and B.O in the lines :skellington: