20. "How To Get Ahead In Dead-Vertising" (Treehouse Of Horror XIX, 2008)
When Homer accidentally kills Krusty the Clown for upsetting Maggie, he's approached by a businessman who informs him that the likenesses of dead celebrities are worth a lot of money for advertisers. Homer quickly agrees to become a hit man that specializes in taking out some of tinseltown’s finest.
Along the way, Homer takes out Prince, George Clooney, and Neil Armstrong in a murderous montage set to The Talking Head’s "Psycho Killer," the episode's highlight. And in a nice bit of detail, there's also a stylish opening sequence for this short that directly parodies Mad Men.