The Simpsons is known for its long running Couch gag at the beginning of each episode. However, that's not the only fun and cool thing that the show has done. Sprinkled across multiple episodes, the show features clips from a movie starring McBain, a movie star in the same vein as Schwarzenegger and Stallone. However, if you put these clips together, you can actually form a full coherent story!
The Simpson fans were clamoring for a movie for years, but they didn't know they already had one inside the show!