7. Juventud Guerrera
Juventud Guerrera was one of the most exciting talents in the world at one point in time, but don't expect WWE to tell you that. They own some of his finest work across ECW and WCW, but he p***** so many people off in his WWE run that history was never going to remember him fondly. He had an ego on him, going so far that he believed The Rock's gimmick was actually a rip off of his own act. There were also drug issues and attitude problems. All these things have counted against him in his career. As for his six months in WWE (surprise, surprise, he didn't last long), he was released after repeatedly violating WWE's rules on aerial moves. Stringent guidelines were in place on what moves couldn't be done, which Juvie repeatedly violated, even doing a 450 splash in his last ever match with WWE. He'd previously broken bones in Paul London's face with that banned move. McMahon got rid of him, also making sure to cover him up in wider WCW / ECW history, ensuring his legacy in North America isn't as famed as it probably deserves to be.