People that don't indicate at roundabouts.
People that don't pull into an empty lane 2 on the motorway when I'm on the slip road trying to join lane 1.
McDonald's when they bring out a limited edition burger but there's no information on what's actually in it, just it's fancy name by a picture. Then I ask the person at the till and they're not really sure.
People that park in parent & child spaces with no child, or their spouse stays in the car with the child so they don't really need the space. I then have to park in a normal space and struggle to get my toddler out without banging my door into the car next door.
Lots more, but I can feel my blood pressure rising just writing these down 