Someone can correct me if they know more, but I always heard good things about Mike Weaver and 'Bonecrusher' Smith.
I met Bonecrusher briefly once. Sorry for stereotyping, but if you did not know who he was, you would never guess he was a boxer; softly spoken and seemingly very learned, he comes across as a teacher/lecturer.... That is not to say because he is intelligent he is automatically a nice person, but I reckon pound for pound he is.
Yes, always came across as a very thoughtful man whenever I've seen him interviewed, especially post-career.