There are so many great episodes of The Simpsons in season 21, but which are your absolute favorite? This list ranks every episode of The Simpsons season 21 from the best to worst, with the help of your votes.
The twenty-first season of The Simpsons aired between Sept. 27, 2009, and May 23, 2010, to become the longest-running American primetime series in television history, breaking its tie with Gunsmoke. Guest stars during season 21 of The Simpsons included Anne Hathaway, Eli Manning, Chris Martin, and Bob Costas.
Which The Simpsons season 21 episode did you like better, "The Color Yellow" or "To Surveil with Love"? Vote up the best episodes from The Simpsons season 21 that you'd like to see at the top of the list.