At the time, Floyd and JMM are the obvious choices. All-time: SRR SRL Hearns Duran Whitaker Pryor Oscar Tito Burley Armstrong Napoles Griffith Gavilan Chavez and Tszyu would both be very interesting. Those are close to being 50/50 fights.
Of course team black supremacist jumps in and says Floyd, while bring up their bogus blood test garbage.
Every guy on that list!! Unlike pac, they are very well versed in the fundamentals off the game unlike pac!! Infact, they would all ko him too!!
Pacquiao was a beast!! an absolute buzz-saw!! Pac is a true ATG as the fighters folks are mentioning are other ATG.
Whitaker, Duran, Leonard, Hearns, to name a few. Hearns and Leonard may not be the most fair matchups due to size, but I actually don't think they would be that far apart in weight divisions during their peaks. Pacquiao's peak year in 2009 when he fought at Junior welter and welter, weighing in 30 hours before the fight. Leonard's peak was 147, Hearns 147 (or 154), weighing in the day of the fight. Pacquiao weighed in the high 140s on fight night. He could of course train/eat differently if he wanted to compete in a lower weight division, but what weight class would Manny have been fighting under the old weigh-in rules? He was weighing in the mid to high 140s on fight night for awhile. At 140, Pryor would be a tough fight. Given some of Pryor's uneven performances against lefties, I favor Manny to win a war. Whitaker would be hell for Pacquiao and just about anyone else. Whitaker wins a decision IMO. Duran's ability to blend offense & defense and shift gears makes me favor him over manny. Duran had a better defense and footwork than Manny. They both had fast feet, Manny's were faster, but Duran's footwork was more educated and he placed his feet better. Duran wins a tough bruising fight. Not sure how Chavez-Pacquiao would go. Pac would have a really tough time against Napoles.
Pacquiao was and still always the same fighter. He was just fighting come forward fighters in 09 hence the so called aura of invincibility