khan - big money fight, if Khan can win his next, no real legacy improvement there 85% win rate, take home pay 30-45 mil. Pac - biggest money fight, adds to legacy impressively, shuts everybody up 75-80% win rate, take home pay 45-75 mil. Martinez - decent money fight, adds to his legacy, shuts the naysayers up 60-75% win rate 20-35 mil.
Its either Sergio Martinez or Manny Pacquiao. If he is serious about getting his 7th title in six weight classes then he needs to fight Sergio at 160 if the Pacquiao fight doesn't happen.
Pac KO followed by Martinez shut out solidifies Mayweather's legacy.. no need for him to fight after that..