#8: Klaus Mikaelson Raised the Stakes on The Vampire Diaries (2009–17)
Klaus Mikaelson appeared during The Vampire Diaries (2009) Season 2, immediately giving the supernatural drama a more dangerous villain. Joseph Morgan balanced Klaus’s cruelty with charm and vulnerability, making him more than a standard antagonist. The character became so popular that he eventually led The Originals (2013), expanding the franchise.
