If someone feel like picking a fight with you which he start by insulting you, what will you do? -ignore -shout at him -take something and throw it at them -kill them -others
Be the bigger person, and walk away. It may seem like your being a chicken, but it's being the bigger person to stop it from turning into something much worse than what it could of been if you just walk away.
I would confuse them. I'm getting insulted, I'll start flirting. (even if they aren't the prettiest color in the rainbow.) It works for me.