Here's Ben Linus, the shifty former leader of the 'Others'. He's expertly portrayed by Michael Emerson who makes you believe that Ben could suddenly stab you in the back at any moment, despite his generally non-imposing appearance.
I always find myself looking into his unmistakable eyes and listening intently to everything he says, always looking for double meanings, trying to figure out Ben's true intentions.
At any rate, it's pretty clear that Ben can take a punch. That guy repeatedly takes a licking and just keeps on ticking...
Update: Okay, after getting the suggestion, I tried my hand at beating up Ben myself and I gotta say, it feels kinda good ;)