Stop line creepers. I don't think this one gets enough attention/
You know, those drivers who, if they didn't already stop beyond the stop line at an intersection, stop behind the line then slowly creep forward into the intersection. They never move immediately when the light turns green, so the only thing they're generally accomplishing is blocking the view for drivers who can turn right on red.
They are the automotive equivalent of people who keep pushing the elevator button because they think it will make the elevator arrive sooner.