4. Michonne Takes Out Penny ("Made To Suffer")
For her first few appearances, Michonne was a mostly silent character; even at the midpoint of the third season, we didn't know much about her. Fortunately, we learn something significant in "Made To Suffer": Michonne isn't really the type to let things go. Still furious that the Governor had sent Merle to kill her, Michonne sneaks into Woodbury to wait for him. She finds his fish tanks of human heads and opens up a cage to find the Governor's zombie daughter. She unsheathes her sword to put the poor child down, but the Governor rushes in. He sees Michonne preparing to stab her through the head and immediately surrenders. "Don't hurt my little girl," he begs, looking more than a little bit unhinged. Michonne, because she is awesome, gives him a moment to think that she might release zombie Penny, then reels back and shoves a blade through the back of her head.
Why It's Great: Michonne sees that the Governor genuinely believes that zombie Penny will someday be as she was, ala season two Hershel, and she actually looks sympathetic for a moment. Aghast, but sympathetic. Then, she remembers that this is the psycho Governor, and that settles the matter. Penny deserved to be put down Michonne just got the added benefit of screwing with him as part of the deal. This kill also led to an amazing fight sequence that beat the hell out of Michonne and cost the Governor an eye. Good call, Michonne.