#4 Perry Saturn
Perry Saturn came into WWE with the rest of the Radicalz - Chris Benoit, Dean Malenko and Eddie Guerrero. Saturn wasn't as successful as his counterparts and it was pretty much his fault.
Saturn faced a local talent named Mike Bell in a taping of WWF Jakked in 2001. In the middle of the match, Mike Bell botched a snapmare and Perry Saturn totally lost it and attacked him for real. He ended up tossing Bell headfirst out of the ring.
Bell could have sued and Vince McMahon never forgave Saturn for this incident. He was jobbed out and paired with a mop for the rest of his WWE run and will probably never return to the company.
#3 Paul London
Paul London was fired after the episode of WWE where Vince McMahon's limo exploded in 2007. The reason behind the firing has reported to have been Paul London smiling while Vince McMahon was "leaving the WWE forever" and walking out of through the back, which was supposed to be a very emotional moment.
London hasn't returned to WWE since.