This could be an interesting exercise. Oxford American asked 134 experts which are the best southern novels of all time. The top ten are here, and there are no real surprises. Glad to see Huck Finn surviving censorship and foolish misinterpretation, though.
Later, however, OA propose to list all 500 or so novels which were mentioned by at least one expert. That could be a fascinating list, and I'll be watching out for it coming online.