nah but seriously, tailgating is definitely up there for me. trucks tend to do it moreso, nothing worse than looking in your rearview and seeing a truck 5cm's off the back of ur car
another one is f**ktards who dont know how to use roundabouts. how hard is give way to the right or people already in the roundabout to remember ffs.
one time some lady was in the turning lane, with her indicator on on my right side, there was nothing in the lane to go straight so i was right to go, however, at the last second she decides she wants to go straight jst as i'd entered the roundabout, then has the nerve to flip me off.... leaving me like.... wtf
oh and the thing about people slowing down to merge onto the freeway, god that shits me.