If someone is being rude to me.. then I just ignore it, I wished I wouldn't have, but I still do...
Now if someone is rude to one of my friends or family members.. I will be rude right back. I don't tolerate that ever.
Being rude is one of the most uncalled for situations. I try to never be the rude person first, but I really think that once the other person has been unecessarily rude it is fair game. It is one of my biggest pet peeves, so when someone is rude I am not going to just "talk it out" or anything nice like that. I am going to be rude right back, and of course I don't want it to turn physical, but it has before and once again I am not going to start the fight, but I won't back down either.