Florida, hands down for me. Gainesville is not only a sweltering, ugly, sandy, hell-hole, but the fans are extremely unwelcoming, often aggressive, and down-right rude.
Georgia is second, for me, but more of an obnoxious and stuck-up breed. Much more tolerable.
Alabama surprised me, this year. Quite tolerant of the opposition (us) and actually seemed to enjoy the fact that we were around.
Side note: have not been to Baton Rouge, but have heard some horror stories from night games.