During classes one day a girl in front of me had her thong halfway up her back. She turned around, thought I was staring at her ass, "Why are you looking at me like that?" "You should stop dressing like a tramp..." She just huffed for a bit, pulled her shirt down, then turned around.
Another day, same girl and a bunch of friends just show up at the head of the line in the cafeteria, right in front of me, behind the tray trolley. I grab one of the girl's by the shoulder, shove her away, then calmly lean over to take a tray off the trolley while all, oh, six of them stare at me while I stand in line trying to not burst out laughing.
And lastly in an Engineering course I was taking, we had to do a Roube Goldburg device as a project. Well mine broke so I walked into class empty-handed that day. Teacher looks at me, "Wheres your machine?" "Well... It came up with witty responses to that question, but it broke."
Not really an insult, but an amusing come-back.