What really ticks you off? If something really bothers you, get it off your chest.

When I'm driving, it has to be arrogant bicyclists who think they own the damn road. They want to ride in the street, but don't want to follow the 'rules of the road'. They run stop signs, then flip off drivers who screech tires to avoid hitting them. They pay NO attention to traffic turn signals or any other traffic signs, usually. You bicyclists out there know who I'm talking about.