33. St. John Powell
Showcase Episode: "Meditations in an Emergency"
Pronounced "Sinjun," which is British for "slimeball," the delightfully evil overlord takes over Sterling Cooper from the Americans and peddles the firm to the hated McCann Erickson, selling out his loyal hatchet man Lane Pryce in the bargain. (Giving him a dead snake in a gift-wrapped box — classy touch, St. John.) Played by Charles Shaughnessy, eternally beloved as Miss-tah Sheff-eee-yeld from The Nanny, although not even the sound of Fran Drescher's voice grates on his nerves like the sound of Lane wishing him a happy Christmas.