I think the worst one ever has to be "Here's 10p for the phone, tell your mum you're not coming home tonight". The reply nowadays would probably be 'F**k off, I've got a mobile you ugly bas***d'.
"I may not be Fred Flinstone but I bet I can make your bedrock"
One of my friends once said to a girl, "Is that a mirror in your knickers because I can see my face in there tonight". She replied, "No thanks. There's already one a**ehole in there!"