I have a very heavy South Philly working class accent. When I was working in the holiday decor design world I often had to present sketches at meetings, and I was told after the first few meetings that perhaps I should take a class to learn how to 'speak correctly.' Luckily, my work spoke for itself and the subject was dropped because I'm proud of the generations of working class people I come from and wouldn't want to lose the accent.
I get a lot of people guess that I'm either from Philly or New York when I'm in, say, Florida.