24. Olenna Tyrell
Alright, Downton Abbey: we'll see your Dowager Countess and raise you a Queen of Thorns. Dame Diana Rigg plays Margaery and Loras Tyrell's grandma and the family's grand matriarch as though she'd rather set herself on fire than utter a single syllable of courtly bullshit. Is that enough to come out on top of Tywin Lannister? Unknown, but it makes for good TV when the two are together, that's for sure.