ur face hahahaha thats a classic ROFLOMGLOL hilarious....the comeback i really hate is 'what-ever'. Its like stupid, it means anything so you dont go
'Your an idiot' "in general?" or 'Your an idiot' "anything".

Children have conventions now!?!?

and another one i hate is 'Your an idiot' "Yeah well your crashNUMBERS!!!"