gothroyalty has been having a good discussion about comebacks. Generally I just ignore the insults I occasionally get; mostly it's just dumb chavs who I can't even be bothered to grace with acknowledgment. Sometime though you just want to retort something really bitchy. Alas, my retorts often turn up ten minutes later which is no good. The more difficult comments have often come from my grandparents who I dismiss as being of an older more bigoted generation who can't help themselves.
I'm going to store some up for next time.