Personal favourites:
Woman: "You hate women."
Me: "How can I hate women? My mum's one."
Woman:
Woman: "You're drunk."
Me: "You're ugly, the difference is - I'll be sober in the morning."
Me: *Joke insinuating they were fat."
Friend of mine: "Was that a fat joke?"
Me: "No, you're a fat joke"
In college...
Me: "I will shag your nan."
Friend: "My nan's dead."
Me: "I will dig her up."
Friend: "She was cremated."
Me: "I'll make a love-paste."
Friend:
Me:
Regale me with tales of your best arguments where you quite clearly pwned them in the face.