I'd put Morales 3rd out of that group. Tough call between Pacquiao and JMM but I'll go with Pac. The discussion seems to be centered on who won the fights between them--a fair enough analysis but one that doesn't lead to a definitive answer (although I vote Marquez in that respect). Aside from the fights with each other, though, Pacquiao was the bigger box office attraction, beat the bigger stars and was generally ranked higher p4p during their respective careers. I think most writers had Pacquiao as the fighter of the decade last decade, and the only other fighters I heard championed for that title were Mayweather and Hopkins, not Marquez. So I think Pacquiao was slightly "greater" as a fighter during his career than Marquez, regardless of how they stack up against one another.