It's Always Sunny in Philadelphia is the Cinderella story of irreverent comedy. Dreamed up by a trio of largely out of work actors, the pilot was filmed for less than $200 with a few handheld cameras and presented to the FX network. The newly created cable company was eager to find an identity for themselves, and decided that Sunny would be the perfect fit for their new lineup. It's an intensely clever show from the very beginning, knowing exactly what it is and the kind of comedy it wants to present. They take the self-obsessed characters that Seinfeld created and turn them up several notches. The show is funny from the start, but it doesn't really take off until they bring Danny Devito on board, to play Dennis and Dee's morally bankrupt father Frank. He brings another level of absurdism to the show, and together he and Charlie make an unbeatable duo. The sky is the limit for this completely over the top character. You want somebody who's going to have sex in a dumpster and eat sausages out of his front pocket? That's Frank. And the show doesn't reach its full potential without Frank.