The greatest pound for pound fighter is?

I didn't pay to see the Mayweather fight. I will watch it when it comes on HBO next week. I will buy his next fight on pay per view if he fights Manny Pacquiao. I miss the glory days of boxing when great fighters fought one another. When Sugar Ray Leonard was boxing he fought Tommy Hearns, Roberto Duran, Wilfred Benitez and Marvin Hagler. You knew he was the greatest welterweight of his generation. He proved it against the best opponents available at his weight class. Is Floyd Mayweather the best pound for pound fighter of this generation? We will never know until Mayweather goes old school and fights the best available opponent (Pacquiao).