29. Lucretia, 'Spartacus'
By any reasonable standard, Lucy Lawless' warrior princess Xena would rank high on a list of TV's greatest heroes. But like the god Janus, she has two faces, and her Spartacus villain Lucretia is the glorious result. Clawing her way up the social ladder at the side of her equally loathsome husband Quintus Batiatus, she views her slaves as little more than sexual playthings and disposable work animals; the revolt led by the couple's prize gladiator is an inevitable response to that kind of cruelty. But there's a tragic element to the fate that befalls her, too — it's not hard to hear echoes of her arc in that of Cersei Lannister, Game of Thrones' similarly dangerous grand dame.