7. Sean Sherk
‘The Muscle Shark’ had a shot at the welterweight title in 2003, losing to Matt Hughes. After a stint with Pride, he came back to the UFC and would beat Kenny Florian for the lightweight title at UFC 64. He defended it once against Hermes Franca and things looked like they were going well for Sherk.
Wrong. After the Franca fight, he tested positive for Nandrolone, a banned steroid, Sherk protested his innocence to the California State Athletic Commission and failed in an appeal. The UFC listened and suspended him while stripping him of his title. When he came back he had another shot at title glory but lost to BJ Penn.
