Of course Steven Spielberg's "Laser Cats" would be the best one.
Bill Hader and Andy Samberg enlisted the director's help for "Laser Cats 7," the latest in their extremely low-budget saga about a future where lasers fire from cats mouths. It quickly turned into an homage to Spielberg's films, with an E.T. doll at the center of the action, host Josh Brolin bringing back one of the creeepiest "Raiders of the Lost Arc" villains, and Spielberg himself making a "Hitchcockian" cameo... that was somewhat less subtle than Hitchcock's.
An aside: Californians came in for a lot of derision this episode, from hilarious "The Californians" soap opera to Bobby Moynihan's San Diego burrito lover in the "Empire State of Mind" skit. In another skit, "We Got More Bounce in California" functioned as a sort of theme song for two obnoxiously popular kids. Maybe the writers couldn't help but notice Brolin's thorough California-ness.
Here's "Laser Cats," followed by "The Californians" (note the slight twist on America's "Ventura Highway" in the "Californians" music).
"Laser Cats 7":