I hate to be the spoiler in all of this but Oscar De La Hoya has the best resume in boxing. Floyd is also known for picking the weakest link in the divisions title holders to accomplish his championship victory. I also do not think Floyd has faced another title holder for a unification bout in his career.

Floyd Mayweather Jr's best opponent's are Diego Corrales, Jose Luis Castillo and Oscar De La Hoya. His other big champions were

Zab Judah after Judah lost to Carlos Baldomir
Arturo Gatti- A shot Arturo Gatti that Oscar beat 4 years earlier and 1 round sooner.
Demarcus Corley on his down slide.
Genaro Hernandez- Oscar beat him 3 years earlier and 2 rounds sooner
Angel Manfredy- No feather in the cap there. A long past his best Jorge Paez and Gatti were his claims to fame.
Jose Luis Castillo- Everyone knows the first fight was a gift.

Top names De La Hoya has faced.
Jimmy Bredahl, Jorge Paez, John John Molina, Rafael Ruelas, Genaro Hernandez (Before Floyd did), Jessie James Leija, Julio Cesar Chavez, Pernell Whitaker, Miguel Angel Gonzalez, Ike Quartey, Felix Trinidad, Shane Mosley, Arturo Gatti, Javier Castillejo, Fernando Vargas, Yori Boy Campos, Felix Sturm, Ricardo Mayorga, Bernard Hopkins, Steve Forbes and Floyd Himeslf. Also add the top contenders he has beaten and you have maybe one of the best resumes in the history of the sport. Also many of these guys were on the pound for pound list when De La Hoya faced them.

I am not saying that Floyd is not a great fighter but resume wise De La Hoya takes the prize hands down. Yes he is undefeated but is he really undefeated against the absolute best the sport and each of his perspective divisions had to offer?