https://campbx.com/main.phpIf you are in the USA... Great option.
I had a larger list, but they all seem to be "less active", and well... shady fronts for foreign accounts that always seem to "get hacked" and "loose your funds"...
This one, and MtGox are my two favorites. But MtGox is in Japan. BTC-e is the next best thing, for multiple trade formats.