Michael Emerson plays Ben Linus on "Lost". Ben's the 2nd coolest character on the show, right behind John Locke, and he's been getting more and more airtime since he was introduced in season 2 because the producers know genius when they see it.
The reason he's cool, even though the show he's on is getting, sadly, less cool, is because he seems to know what's going on on the island even though no one who's been watching the show for the last 76 years does. We all envy him because he probably doesn't have to watch any more episodes to find out what the eff is going on.
More than that though, I like Michael Emerson because JJ Abrams and the "Lost" crew wrote a great, mysterious, continually-surprising character, and Emerson nails the role every week. Part of what makes him an actor you can't help but watch is his brilliant use of voice. It raises creepy to new levels.
And he uses that voice to great effect for this awesome bit on "Late Night with Jimmy Fallon", reading a children's rhyme in his patented creepy-genius voice. If they were casting "Silence of the Lambs" right now, I guarantee this guy would be in the lead for Lecter. Anyway, good stuff. Made me laugh.