#1 The Undertaker

There's little argument when one describes The Undertaker's character as being possibly the greatest gimmick in the history of pro-wrestling. It came at a time when goofy characters were a thing, and the gimmick of a Deadman with supernatural powers was the right fit for that era. The Undertaker was more than a flash in the pan though, and went on to enjoy a three-decade career in WWE.
Shane McMahon once revealed in an interview that Vince McMahon was the one who came up with the gimmick. During a discussion with Paul Bearer, Vince learned that he was a mortician. Vince came up with The Undertaker character and paired Mark Calaway with Paul Bearer.
Cody Rhodes' uncle is a WWE Hall of Famer. More details HERE.
The Undertaker went on to win several World titles, and has only been defeated two times at WrestleMania. He is a guaranteed future Hall of Famer, and will be remembered for donning what many considered a goofy gimmick, and turning it into a top WWE attraction. Fans can check out The Undertaker's latest WWE Network special named Undertaker: The Last Ride for a behind-the-scenes look at his career.