5. Triple H
It's honestly so impressive how Triple H could pivot from one of WWE's most adored good guys to one of its most despised heels. The Game has made a career out of it, switching personas on a dime, and it extends all the way back to his early days as Hunter Hearst Helmsley, with fans' hatred for him growing with every heel turn.
From D-Generation X to The Corporation (and the Corporate Ministry), the Triple H character had a way of getting under people's skin and the company was able to capitalize on that by placing him at the forefront of multiple major factions.
In 2001, he was at the top of the company with Stone Cold Steve Austin as part of the Two Man Power Trip, relentlessly assaulting anyone who got in their way. Back then, the heels could get away with more, and that's one of the things that heel Trips did best. And then you have his next heel turn in 2003, when he became the World Heavyweight Champion, formed Evolution, and came after major stars like Goldberg, Kane, and Randy Orton.
Even when he went part-time, he formed The Authority and became the most loathed man in the company when he made it his mission to prevent Daniel Bryan from becoming WWE World Heavyweight Champion. It was the perfect story for Bryan's eventual ascension to the top of the food chain, and just the most recent example of how natural a heel Triple H is.
Even though he has officially retired from in-ring competition, he could very easily return to his heelish roots as the leader of another corporate faction. The man is so easily able to slot into that villainous persona, and even though he's one of the most beloved good guys in WWE history, he has achieved even greater levels of success as one of its best ever villains.
No one has been a more long-standing thorn in the WWE Universe's side than heel Trips.