Whitaker. I believe Floyd has shot into the top 100 ATG like a bullet, but Whitaker still outranks him and would jab his pus off all the way to the win, probably by a good margin.
Mayweather would make a good sparring partner for Whitaker, although in a real fight he'd probably get decimated.
Under today's scoring system offense and aggression win over pure defense under today's judging I don't see Whitaker getting a decision. Floyd, I think would Pernell would have to fight him in the pocket to have a chance at winning.
I think that Chavez, Duran, Maestrito Lopez, Tito Trinidad, Sergio Martinez, Oscar De La Hoya, Margarito would have given him tough fights and had good chances of beating floyd