Check out The Simpsons' homage to David Letterman. The comedian announced his retirement from TV last week.
Replacing the usual ride to home, in this couch gag the family is in a cab stuck in Manhattan's traffic. Then they decide to get out of the cab and run because apparently they are late for something. After Homer gets punked by a street hustler in a three-card monte game, they get to the Ed Sullivan Theater. They can't get in because they are not in the list, so Homer headbutts the guard, runs in with the family, headbutts some producer at the door of the studio, and then runs the stairs to the stage. Finally, they sit on the couch next to Letterman as he does his usual bit.
The gag closes with Paul Shaffer's band playing The Simpsons' theme and a succinct farewell: "We'll miss you, Dave."