2. Jaqen H'gar: The Silent Assassin
Jaqen H'gar feels he owes Arya Stark three lives because she rescued him and two other men from a certain and potentially very painful demise. But how does one pay back lives? By killing, that's how. And kill he does - all that he asks of Arya is that she give him three names, and he will see to the rest. The first man is the Tickler, who was responsible for torturing the prisoners; he winds up with his neck snapped. The second man, Amory Lorch, is about to get Arya into all kinds of trouble with Tywin Lannister; he dies mere seconds before he can report to his Lord. The third man is Jaqen H'gar himself - that is, unless he helps Arya and her friends escape Harrenhal. He tells her that her party will walk through the gate at midnight, and they do exactly that as the guards who were meant to be watching it are all dispatched silently. A man is true to his word, and a total badass, apparently.