Community (2009)

"Abed's Uncontrollable Christmas," Season 2, Episode 11 (2010) Abed wakes up convinced the world has turned into stop-motion animation, and the whole episode is animated that way, in the style of the old Rankin/Bass holiday specials. It looks like a novelty, but underneath it is one of the show's most affecting stories about Abed and why he retreats into television, which is why it sticks with people beyond December. Character animator Drew Hodges won an Emmy for his work on it. Watch it after a few earlier episodes, so you already care about Abed when the twist lands.