There's always some starfish in a brand new Mercedes-Benz SUV/BMW/Acura tailgating me when I'm doing 5 over the speed limit; makes me want to slam on the brakes and have him rear end my truck, then sue him for damages.
also, there's almost always a women driver in a Ford F350 trying to park in a parking garage, and when she finally manages to get in a space, she takes up two spaces, juts out into the driving area, and causes traffic to stall.