No, I've never been called a snob, at least not to my face. I've been referred to as aloof, which is pretty close, but never a snob.
Yesterday however...I was called a coward by my brother in law's mother because I wouldn't go inside my sister's house and say hello to everyone. It was partially because I have been sick and didn't want to spread my germs, and partially because my brother in law's family are all loud, outgoing people who scare me. She said, "Come on in, don't be a coward." I was a little bit shocked and offended, but I considered the source and tried not to let it bother me.