Quote Originally Posted by Lyle
While Mayweather's style would cause EVERYONE to have trouble with him there are some people that would give HIM trouble!

Chavez
Duran
Mosely
De la Hoya
Camacho
Pep
Sanchez
Ray Leonard
Benny Leonard
Tommy Hearns
Trinidad
Wright
Benitez
Well, most of these are all-time greats, and would give anyone trouble. Whitaker is a pretty big omission from your list. Especially considering that he may the closest comparison to Floyd other than Willie Pep.

Of those you listed, I actually think Hearns is the prototype for the type of fighter who could give Floyd trouble. Tall, long fighter with one punch KO power. Guys who need high volume to KO guys (Chavez for example) can't beat a fighter like Floyd because you can't hit him time after time.
Hearns could use his size to constantly keep Floyd within range, and potentially catch him with a straight right.
Trinidad also had one punch KO power, but his left hook wouldn't get to the target nearly as fast as Hearns' right hand.