#2 Vince McMahon - 1997

While WCW had Hulk Hogan make their biggest heel turn in history by forming the NWO, WWE had their biggest heel turn ever a little over a year later, but this one was far more real than any to come before it.
Everyone knows the story by now, WWE Champion Bret Hart is leaving the WWE for WCW (on Vince's recommendation), a paranoid Vince fears there may be a repeat of when Alundra Blayze binned the Women's Championship on Nitro or something worse, so Vince decides to screw Bret out of their planned finish. WWE's most infamous moment is born.
What was also born here was the heel character of Vince McMahon. Before the weeks leading up to this, he had only ever been liked to be referred to on TV as a commentator but brought himself into Bret and Shawn Michaels feud when it began to touch reality.
Now to be fair, the Mr. McMahon character didn't truly evolve until a few months later in his feud with Stone Cold Steve Austin, but from Survivor Series onward, Vince McMahon was detested by most fans.