1. The Artist
WCW turned Prince Iaukea into the The Artist Formerly Known as Prince Iaukea. A funny idea when you first hear it, but it got old after a while. Pretty annoying gimmick.
2. Vince Russo
Putting Vince Russo on TV was a big mistake. He was brought to WCW to make things better. But he got involved in feuds on TV and made things worse.
3. Big Bossman
Wow. Ten years ago he was cool. After horrible feuds with Al Snow and the Big Show in 1999, the Bossman teamed up with Prince Albert and Bull Buchanan in two unsuccessful teams. He spent a lot of time wrestling on WWF Jakked and was out of action for some time.
Runners up: X-Pac, Big Show, Goldberg, Rikishi, Steven Richards, David Arquette, Demon, Eric Bischoff, Mideon, Scott Steiner, Stephanie McMahon-Helmsley, The Wall