5.08 Changing Channel
Synopsis: The Trickster (guest star Richard Speight Jr.) throws Sam and Dean into an alternate universe where they are characters in different television series, including a sexy medical show, a Japanese game show, a forensics show and a sitcom. The brothers realize the only way to get out of this world is to play along and become the characters in the shows. However, Castiel (Misha Collins) appears and warns them this universe is dangerous and they must get out before they become trapped. Teleplay by Jeremy Carver, directed by Charles Beeson. Episode airs on November 5.
I was watching Scrubs the musical last night.. and I did a fanvid last year which was a Scrubs and Supernatural crossover.