4. Lena Headey
Lena Headey is more than just the queen of Westeros -- she is the queen of sass. She can obliterate you with a simple raise of an eyebrow. So why is she never the one that we talk about when we're discussing Game of Thrones? Yes, Peter Dinklage is doing possibly the best work of his career as Tyrion Lannister, but it takes two to tango, and she's pulling half the weight in their highly celebrated scenes. I'm being totally serious when I say that I would gladly sit down and watch them read the dictionary to one another. She's got as much attitude as the Lannister family has gold, but she's so much more than that. Headey is able to portray one of the most difficult character types -- the one with the skewed moral compass. I would never go so far as to say that she's evil, but she has her own very specific views of right and wrong that don't necessarily mesh with popular opinion. It's not easy to play a character like that sympathetically, but she somehow manages to pull it off. That plus her performance in the prematurely cancelled Terminator series are more than enough to land her on this list.