#1 Raven
This is one of WWE's biggest crimes. Raven is without a doubt one of the best wrestlers ever to compete for ECW and the best character ever to come out of ECW. After a forgettable run in WWE in the early 90's as Johnny Polo, Scott Levy joined ECW in 1994 as Raven, a character to appeal to fans of grunge music and generation X. Paul Heyman has described Raven as being Nirvana and Pearl Jam, while many in WWE were 80's hairbands.
Raven had the biggest and best feud in ECW history with Tommy Dreamer, which ran on and off from 1994 until Raven left ECW for WCW in 1997. Raven was a two-time ECW World Champion and four-time Tag Team Champion and was always presented as a top star. The character was damaged in WCW thanks to some colorless booking, but it was nothing that he couldn't recover from.
After a brief return to ECW in 1999, Raven returned to WWE in 2000. Many fans had hoped to see him face off with The Undertaker, Kane and some kind of work with Mick Foley. It wasn't meant to be, Raven would be forever stuck in the hardcore ranks, where he would become a 27 time WWE Hardcore Champion, according to WWE records, 39 by his count.
He had memorable hardcore matches at WrestleMania 17 with Kane and Big Show, and with Rhyno at Backlash 2001, but nothing else of note. To make matters worse, Raven was forced to wrestle on just Sunday Night Heat for the majority of 2002, after losing a Loser Leaves RAW match to Tommy Dreamer. WWE didn't even care enough to move him Smackdown.
Raven was released by WWE in January 2003 and managed to revitalize his career in TNA wrestling, where he had a successful 6 or so year run. During this time Raven would be featured as a top star for several years and become the NWA World Champion.
To date, he is one of very few wrestlers to have wrestled for WWE, WCW, ECW, TNA, and ROH.