20Saved: Joseph Morgan (Klaus Mikaelson)
Klaus Mikaelson was originally introduced on The Vampire Diaries as the baddest of the Big Bads. As an Original Vampire (who was also the original werewolf-vampire hybrid), Klaus needed a doppelgänger to allow his werewolf side to be free so he could sire his own army of werewolf-vampire hybrids.
was only meant to last one season on The Vampire Diaries, but Joseph Morgan's complex portrayal of Klaus made the character a fan-favorite, and his epic romance with Caroline Forbes is still one of the most fiercely defended in The Vampire Diaries universe. The Originals wouldn't exist without Morgan's strong acting. The series' popularity hinged on his ability to successfully show his character develop.