5. Michael Emerson
As TV anti-heroes go, LOST's Benjamin Linus is up there with Spike from Buffy if not the likes of Tony Soprano, Walter White, and Vic Mackey. Supposedly favorite son of the mystical Island and leader of The Others, Ben is plagued by an inferiority complex and a chip on his shoulder, which contribute to making him a vindictive, nefarious, often deeply unlikeable human being. Even so, the depth of humanity that Michael Emerson displayed in the role - the look of utter shock on his face when his daughter Alex is murdered in season four is one of my all-time greatest TV moments - transformed Ben from a bit part (he was only originally contracted for a few episodes in season two) into a series regular, winning Emerson an Emmy in the process. As shown in this clip, Emerson can seesaw from genially charming to unsettling creepiness in an instant. There's something almost reptilian about those heavily lidded eyes and you get the feeling that, even as a prisoner, he is utterly in control of the situation. Sowing the seeds of discord between Locke and Jack, playing on their fears and insecurities, Emerson's Linus is a master manipulator, though his calm insidiousness may more suggest a villain like The Riddler, someone whose threat is perhaps more understated than the balls-to-the-wall crazy Joker. As Jigsaw's assistant, Zep Hindle, in the original Saw and serial killer William Hinks in The Practice (for which he won an Emmy - one of nine guest actors/actresses to do so on the show), Emerson's mercurial nature always shines through. Emerson voiced The Joker in the recent animated adaptation of Frank Miller's The Dark Knight Returns and, while he may not have the hulking physical presence of the character himself, he's more than talented enough a performer to carry that through to live action. Just because a man may seem unassuming doesn't mean he isn't capable of losing his marbles - a lesson learned from Linus himself, Hinks, et al. In any case, Michael Emerson definitely as a quality about him that suggests he could get under Batman's skin and, currently starring in Jonathan Nolan's Person of Interest, he's certainly working with the right group of people to draw attention to him as a candidate (ha! semi-obscure LOST joke).