In my area, you do have a little bit of a difference between urban and rural accents and speech patterns. I was raised speaking decent grammar and with the less pronounced accent, but I can fake some of the bad grammar that is typical for my area and a little bit of the rural accent without much effort in order to not sound too stuck up. It's hard to ditch the vocabulary I've picked up from reading, though. So it only works for short, casual conversations.
One other stereotype I sometimes run up against is religion, because I'm an Evangelical Christian and Evangelical Christians have a mostly-deserved reputation for being obnoxious and ignorant. I don't go out of my way to tell people I'm Evangelical and I try to be respectful and considerate to people, so I only get crap in an indirect way most of the time. It sometimes bothers me, but I can see where folks are coming from, so that is one stereotype I make an effort to defy.