#7 The Undertaker
While he might not have had as many ups and downs like a Jeff Hardy or a Kurt Angle, The Undertaker is synonymous with WWE.
After failing to find his footing in WCW, he signed with WWF and debuted at Survivor Series in 1990. The rest is history.
His career is filled with first-ever matches in WWE, like Hell in a Cell, Casket matches, and Buried Alive matches.
Whether or not he came up with the ideas for the matches isn't as relevant as the fact that he became known for participating in these types of matches and keeping kayfabe in his character alive.
The Undertaker is the best gimmick of all time and the fact that he had an undefeated streak at WrestleMania for over 20 years is the stuff of legend.
Sure, the outcomes are predetermined, but what started out as a simple streak of wins at the show turned into a right of passage for some superstars and akin to a championship match at the show itself.
If nothing else, he was the epitome of a loyal, locker room leader who commanded the respect of the entire roster and even his boss.
It would be interesting to see a story crafted around how he impacted not only the WWE but the industry as a whole.