#4 Dean Ambrose
Dean Ambrose, or Jon Moxley as he is known now, is no longer with the WWE, leaving the company earlier this year after a phenomenal career with them. Ambrose was an indie darling, having been known for bloody death matches, following which he went on join WWE's FCW promotion.
The rest, as they say, is history as Dean Ambrose, alongside Seth Rollins and Roman Reigns went on to form The Shield, one of the most dominant factions in recent history. Ambrose himself went on to become a Grand Slam Champion and a Triple Crown Champion, winning numerous titles in WWE.
But Ambrose wouldn't have thought that he would be such a huge thing in WWE when he wrestled three times in 2006 and 2007 and lost all three times on WWE's Velocity and Heat shows. A decade later, Ambrose was holding the WWE World Heavyweight Championship!