Haven't watched the rest of tonight's "Simpsons" yet, but the couch gag -- in which Homer evolved from single-cell organism to 21st century man, with stops through prehistory and the Renaissance -- was definitely the longest I've ever seen and maybe the funniest. (Lenny and Moe's cameos alone were brilliant.)
Tell me I'm wrong. Name a better one.
UPDATE: So it's on YouTube, for now. Watch it while you can, and hopefully if NewsCorp has it pulled, an official version will go up on Fox.com somewhere.