Best teeth I don't know but I would gather the better the face the better the teeth... if the face shows variance between the cheek and the eye socket and the tip of the nose and has good natural lips I would gather the maker has an attention to detail. If the figure has a generic smoothy quality I would not expect much from the inner mouth and other details. I think good eye socket texture usually is the sign of good work overall. I like ApoGraphix by Fenrissa and Thorne Sarsa for textures. I wonder if you should also try shader tricks like SSS? I used to give just a touch of transparency to teeth back in P4.