Dr Bronner's, no question about it. This is the first soap I found that I actually like, for one very important reason: you can rinse it off. It seems like almost every soap leaves a sort of film (moisturizer, perhaps) that drives me nuts. When I shower I want to feel clean when I'm done, not covered head-to-toe in an irremovable film, please. It is also the only soap (or shampoo, but it's kind of dry) you will ever need. Seriously - I don't use anything else for cleaning anything anymore.
It's also family-run by ecologically-friendly people that pay their employees well and donate excess proceeds to charity. As an extra bonus the bottle is covered with Dr. Bronner's spiritual ravings in order to bring humanity together in the ALL-ONE-GOD-FAITH. Someone apparently crucified themselves in Chicago (unbeknownst to Dr. Bronner) to promote the soaps (though he was taken down before he died). I find that somewhat difficult to believe, but it appeared in the Chicago Tribune... Here's another article on the company
ALL ONE OR NONE!! !!