Like Arrested Development before it, 30 Rock manages to find ways to stay fresh lesser sitcoms can only dream of. A good example is this episode, Fireworks, which cements the Development comparisons by having Will Arnett, aka Gob Bluth, as a guest star.
Arnett plays Devon Banks, the pioneer of ten-second sitcoms, a sleazy, opportunistic SOB who's after Jack's job. After finding out his competitor is gay and has a crush on Kenneth, Jack decides to use this to his advantage and figure out what Banks is planning, since no one is convinced his major idea (fireworks) will impress Don Geiss. Liz, on the other hand, is startled when she sees Floyd (Jason Sudeikis) go to church, since in her opinion it's weird to do so on a Tuesday. As for Tracy, his world is turned upside down when a DNA test he took for a paternity dispute reveals he's a direct descendant of none other than Thomas Jefferson.
Yes, most (actually, all) of these ideas are silly, but as Seinfeld brilliantly taught, silliness is often the key to clever comedy. And as usual, the witty script is supported by perfectly timed comedic acting: Rip Torn returns as Geiss to great effect, and Arnett, deservedly praised for his shamelessly shallow and moronic Arrested Development character, comes very close to stealing the show, Banks being essentially a more intelligent, but equally malevolent, version of Gob. However, his effort is beaten to the top spot by the most unexpected of cameos: a ghostly appearance by Thomas Jefferson, played with unrelenting, over-the-top glee by... No, I can't reveal that detail. It's just too funny to spoil. Where do they come up with this stuff?