Here in Las Vegas, everyone is from somewhere else. So "Where are you from?" is a stock question when meeting someone. I always say "Detroit".

By the same token, when I'm away from my home in Henderson, NV., and I'm asked where I'm from, I always say "Las Vegas".

It's just common sense. Give the most logical and understandable answer. Anyone who says "Washington Township" needs a good butt-kicking, IMHO.