The op noted that current fighters like GGG, Ward, Kovalev are "undetermined", so implied that they could be considered and that the topic is not just best from the first decade of the century, but from 2000 to present. Which explains my inclusion of Ward and Gonzalez. Calderon deserves his spot as he reigned for almost a decade, and did fight most of the top contenders, like Alex Sanchez, Tunacao, Cazares. Longevity is the most important criteria when comparing accomplishments of 16 years. Which is why Hopkins could even be considered greater than Mayweather. Morales' opposition and dominance between the second and third Barrera fights was better than Barrera's, and is primarily what keeps him high for me. Shutting out and beating down Espadas, Ayala, Hernandez, Chavez. What made the third fight such a great win for Barrera is that he beat a greater Morales than he fought the second time. If you rate Barrera highly you can't rate Morales too far behind. If you rank Mosley higher than Oscar it can't be by much. If you want to say Oscar didn't do much more than beat Vargas and Mayorga who Mosley also beat, you could also say Mosley didn't get a single win over a decent fighter from 2001 to 2005. I guess I overrated Oscar's better performance against Mayweather, but will move Mosley higher for beating Margarito. I think you have to have Tito above Mosley and Oscar, for his run between the Oscar and Hopkins fights. But I don't think he was the same guy when he came back and lost to Wright, so don't credit Wright too much for that. When ranking all time you're stressing and dominant they were in their own prime and wins over prime fighters throughout their career. Wright just doesn't have the wins over prime greats that those three do. Vazquez is not too high at all. He reigned as champion for over three years, was a p4p talent, then beat Marquez in two of three, who had an even greater championship reign than Vazquez. I'm a big Tszyu fan, but I have a hard time putting him higher than I have him. He was pretty inactive, Judah, Sharmba Mitchell, and Tackie are his most notable wins, and losing to Hatton hurts him. No Tyson wasn't a significant win for Lewis, but Tua was a greater than anyone Vitali beat, and Lewis showed his true level in the the revenge Rahman knockout. And that a past his best Lewis beat Vitali keeps him higher all-time, regardless of the rest of Vitali's career. Wladimir had greater longevity through the century than both, so is deservedly high. As this covers 2000-2016 of course Andre Ward deserves inclusion. In fact I've reconsidered, and think the Abraham, Froch, and Dawson wins should move him above Tszyu. With slight modifications: 1. Floyd Mayweather 2. Bernard Hopkins 3. Manny Pacquiao 4. Juan Manuel Marquez 5. Marco Antonio Barrera 6. Erik Morales 7. Roy Jones 8. Joe Calzaghe 9. Israel Vazquez 10. Rafael Marquez 11. Felix Trinidad 12. Wladimir Klitschko 13. Miguel Cotto 14. Shane Mosley 15. Oscar De La Hoya 16. Winky Wright 17. Lennox Lewis 18. Vitali Klitschko 19. Andre Ward 20. Kostya Tszyu 21. Pongsaklek Wonjongkam 22. Sergio Martinez 23. Nonito Donaire 24. Roman Gonzalez 25. Ivan Calderon