19. Oz
Appeared in: Buffy the Vampire Slayer, Angel Guitar playing, chilled out Daniel "Oz" Osbourne first turned up in Buffy's second season, and we soon discovered (to no one's surprise, since Sunnydale played host to a ton of monsters and other creatures) that the kind natured Oz happened to be a werewolf. No biggie - just lock him up in a cage in the library every full moon! Oz was portrayed by Seth Green, being Seth Green, but before we knew who Seth Green was - so it was fresh. As silly as it sounds, the character worked and became a fan favourite, even if the werewolf effects basically consisted of some bad CGI and a guy in a moth-eaten looking suit. What makes Oz a great character? Well, a show about the supernatural needs a werewolf! Beyond that, however, it's the way Oz's struggles with his werewolf side reflected the changes in personality and emotions that all teens eventually go through. The werewolf was both literal and figurative in the case of Oz, and it was often the real-life struggles Oz encountered that hit home the most - primarily his struggles in his relationship with Willow, and his discovery that it was her, a girl he loved with all his heart, that triggered his animal side. His sacrifice, leaving for the sake of her safety, at first, and then stepping away when he realized that they weren't mean to be, resonated with fans, and while he was never a crucial part of the show (it survived just fine without him), he was always a welcome face when he did turn up.