Played: Celeste "C.C." Cunningham, starting in season 2's "Somebody to Love"

Though Falco had funny moments on "The Sopranos," she had never done an out-and-out comedy before her role as the Democratic congresswoman — and subject of the Lifetime movie "A Dog Took My Face and Gave Me a Better Face to Change the World: The Celeste Cunningham Story" — who becomes one of Jack's funniest, most unlikely love interests. Afterwards, when she had retreated to more familiar territory in Showtime's "Nurse Jackie," she said she couldn't imagine ever doing a sitcom again, because she felt she had no idea what she was doing, and when she won an Emmy for that show, she insisted, "I'm not funny." She could've fooled us, though, given how seamlessly she fit into the show's world, whether arguing on behalf of orange children, acting turned on when Jack tells her to take off her pantsuit, or even getting in drag as plumber Mr. Spoonatelli to keep their forbidden romance a secret.

- Alan Sepinwall