People who talk on their cell phones while at the drive-thru window. (I work Drive-Thru cash at my workplace.) Not only is it RUDE but it holds up our line. Especially when we ask you if you'd like and condiments numerous times then finally get fed up and hand you the bag with no condiments and you ask for ketchup. "Hey, I'll call you back in a few minutes..." EASY!

People who butt their noses into other people's business.

Slackers at work.

"When I make eye contact with you and say "Good Morning" at least nod."
-This especially pisses me off.