#3 Vince McMahon
As well as being one of the most infamous moment in the history of wrestling, the Montreal Screwjob also heralded one of the most significant heel turns in WWE history.
Unlike the other heel turns on this list, this was completely unscripted and was designed to force the WWE championship off Bret Hart to prevent him turning up on WCW with the title. As Bret's match with long-time rival Shawn Michaels at Survivor Series 1997 came to a close, Vince McMahon came to the ringside area and called for the bell as Michaels locked Hart in his own signature move, the sharpshooter. Hart reacted by spitting at McMahon and trashing the announce desk as the event came to a close.
This moment saw the transition of Vince McMahon, the babyface play-by-play announcer to the evil Mr.McMahon that would go on to feud with Stone Cold Steve Austin. McMahon became recognised more widely as the owner of the company and abused his role to hold down other top stars.
It was a significant moment in wrestling history, not only for the period that followed, but a real life event that triggered a boom in interest and ushered in the Attitude Era.