I used to have a rather thick Californian accent growing up and was teased for it when we moved to Minnesota. I still have it, I'm just good at accents so I can hide it well.
So far accents I can do well are :British/Aussie/New Zealander, Russian, Scottish, Irish, Asian, Southern US, Northern US, Western US, Brooklyn, Chicagian, German, Norwegian, and Klingon.