Re: Better Resume/Legacy Floyd Mayweather Jr. or Marvelous Marvin Hagler?
There are three ways to answer this:
1. The set of people who know the least will say Floyd, excluding Pac fans
2. The set of people who really think they know what they're talking about will say Hagler
3. The people who actually know what they're talking about will say Floyd
And it's clear cut. Hagler had 12 middleweight title defenses. His best win is against Hearns, which I think is better than any of Floyd's wins...but Hearns had moved up from welter and beating him at middle was not an impossible feat. Other than that, Hagler's resume is weak compared to Floyd's. It features wins over Hamsho (good), Mugabi (good except Mugabi accomplished absolutely nothing in his career other than losing to Hagler), Duran (not really that good), Antuofermo (past it), and Minter (decent). But that's about it.
I won't break Floyd's resume down, but he's beaten more champions and HOFers/future HOFers, made more title defenses, had success in many weightclasses, won more titles, and had more longevity than Hagler. And he's undefeated and still going. The case is already closed on Floyd's career being better.