Fighters who are good people-Lennox Lewis and Floyd Patterson are and were great ambassadors for the sport. The former could be an MP.
I don't personally know any fighters but from the interviews I've seen Emile Griffith and Sean O' Grady always seemed like good guys.
Salvador Sanchez was a very humble individual, always had praises for his opponents after a bout, he was a very clean fighter that did not need an edge to resort to dirty tactics in the ring. Archie Moore was another fighter with class, he built a Boys Club for us in our neighborhood in Dec 1969. Moore even paid for an eye operation for a youth in San Diego, California, whose parents could not afford to pay for the operation.
Former Middleweight Champ Terry Downes was responsible for raising the money to buy 17 minibusses for under privileged children.
Terry was a tremendous character. His book, " my Bleeding Business", is a great read although readers in the States may struggle with the fact it is written in his native cockney dialect. A little known fact is that Downes was selected to represent the USA in the 1956 Olympics until the Authorities discovered he was a Limey. He was a serving US Marine at the time.
Muhammad Ali. He inspired so many people. Every single person who has met Ali has a positive story talking about the man's generosity and willingness to chat with random strangers.