20 years of the Simpsons
Matt Groening's animated characters started in the late 80s on Tracey Ullman's show and grew into a global phenomenon
Simon Cowell riles up Homer when he parodies himself as a tough school admissions committee member who grills Maggie.
Homer Simpson has a chat with guest star British Prime Minister Tony Blair when the Simpsons travel across the pond in The Regina Monologues.
Lisa tries to impress her new Waverly Hills classmates by telling them she knows pop star Alaska Nebraska (guest voice Ellen Page), but Lisa is in for a surprise when Alaska Nebraska comes to town.
Jack Bauer (guest voice Kiefer Sutherland) and Chloe O'Brian (guest voice Mary Lynn Rajskub) help Bart and Lisa, agents of the Counter Truancy Unit (CTU), stop bullies Dolph, Kearney and Jimbo from releasing the ultimate stink bomb at the school's annual bake sale.
Ringo Starr (as himself) in the "Brush With Greatness" episode, 1991.
On a Trading Spouses-type show, Homer is forced to take in a controlling wife, while Marge moves in with a beaten-down husband, Charlie (guest star Ricky Gervais), and his perfect son.
The Who guest star on the 250th episode of The Simpsons, Rock Superstars.
Lisa and guest stars Paul and Linda McCartney in the "Lisa The Vegetarian" episode, 1995.
The iconic Bart Simpson, voiced by Nancy Cartwright.
The Simpsons in a 20th-anniversary publicity shot. From left, Bart, Maggie, Homer, Marge and Lisa.