The Simpsons “Best. 20 Years. Ever” celebration culminated in January of 2010 with a documentary special entitled “The Simpsons 20th Anniversary Special in 3D on Ice” which aired on January 14, 2010 - the 20th anniversary of the series’ debut (not counting the Christmas special, Simpsons Roasting on an Open Fire, that aired 2 weeks earlier). Despite the title, the documentary is in 2D and not on ice until the end, where the family is seen skating (it is not seen on 3-D to us just to the Simpsons characters watching the TV).