I'd say Kessler, Trout and Martinez are the most obvious examples of fighters with class in and out of the ring. You never see this guys storming out of the ring when losing. You don't see them fouling and showing up people in the ring. I saw Ward give Kessler about 5 headbutts, but he he was too sportsman like to foul back and start butting himself. Really made Ward look like the lesser man in that fight. Same with Martinez and Trout. Really great guys. Total respect for those guys.
Floyd Mayweather He's a drug crusader for the sport, if every boxer was like him we would have a clean sport.
Lomachenko He didn't complain about Salido's constant cheating in the postfight interview and he said he wouldn't do dirty stuff even if the opponent does it against him.
Andy Lee. Personification of the old skool fighting gentleman. Will fight anyone, never makes any excuses if he loses, and is gracious in victory. We need more fighters like Lee.
Richie Woodhall and Jon Thaxton. Always liked Gavin Rees after he grew up and stopped punching people at funerals.
Anthony Crolla is a real class act outside the ring, probably as nice and humble a guy as you could wish for, spot on with Kessler though, GGG is class as well.