Roberto Duran comes to mind.

Marvin Hagler
Sugar Ray Leonard x3
Thomas Hearns
Esteban De Jesus x3
Carlos Palomino
Lou Bizzarro
Ken Buchanan
Wilfred Benitez
Davey Moore
Robbie Simms
Hector Camacho x2
William Joppy
Jorge Fernando Castro x2
Vinny Pazienza x2
Iran Barkley
Pipino Cuevas
Kirkland Laing
Edwin Viruet x2