People who drive in the left lane on the highway at or below the speed of people driving in the right lane.
People who hold prolonged conversations in front of the coffee pot.
People who get to the front of a long line at the coffee shop/food place and then take their time deciding what to order.
People who don't use turn signals.
People who take carry on bags on board the plane when the bags clearly aren't going to fit anywhere.
People who reply to listserv emails asking to unsubscribe.
People who reply to people who reply to listserv emails asking to unsubscribe.
Feel free to add you own in the comments. A version of this especially for academia is coming soon, so you may want to hold off on relevant comments until then.