Alright i can think of a few:

Howard Jones (killswitch engage)
Zack De La Rocha (RATM)
Lajon Witherspoon (sevendust)
Corey Taylor (slipknot)
Alexi Laiho (children of bodom)
Max Cavalera (sepultura/soulfly)
Layne Staley (alice in chains) if he wasnt dead