Oh my ... there are so many....but off the top of my head:
"The City of New York Vs. Homer Simpson"
("Khlav Kalash! No bowl, stick! Mountain Dew or Crab Juice.")
The "Treehouse of Horror" with Homer and the time-traveling toaster
("I wish, I wish I hadn'ta killed that fish.")
Spinal Tap concert in Springfield
("Good night, Springton. There will be no encore!")
The Ramones play Mr. Burns' birthday party
("We'd just like to say this gig SUCKS!" "Yeaahh, up yours, Springfield!")
The Simpsons hire "Shary Bobbins" to care for the children
("Don't think it's sour grapes but you're all a bunch of apes!")
Troy McClure's sham marriage to Selma Bouvier
("I hate every ape I see, from Chimpan-A to Chimpan-Z, you'll never make a monkey out of me!")
The X-Files episode would make my list too.