Here's one that never actually happened: Don Bellisario wanted to do an episode of Quantum Leap where Sam leaps in as Thomas Magnum from Magnum, P.I.. But there was an episode earlier in the series where a character is seen watching that show on T.V.
You misunderstand my reason for starting this thread. It wasn't my "original crossover idea". My idea had nothing to do with crossovers. I wish to write a list of all the episodes, movies, novels, comics, reference books and video games in a franchise, kind of like this list here: http://starwars.wikia.com/wiki/List_of_all_Star_Wars_media Ideally, everything in the list should be arranged in order of release but there are some TV shows like Firefly that were shown in an order that doesn't make sense and were release on DVD in a different order. Unaired pilot episodes were never shown on TV at all. This is the reason for two of my recent threads: http://www.trekbbs.com/showthread.php?t=87660 http://www.trekbbs.com/showthread.php?t=87659 In these situations, using DVD order is preferrable. But DVD order can't be used if some episodes exist on more than one DVD collection. Therefore, there needs to be something special about a DVD collection for DVD order to supersedes airdate order. The DVD collection must have deleted scenes, or it must be a Blu-Ray collection. Either way works for Firefly. But if I find an episode that exists in two different DVD collections and BOTH of those collections have deleted scenes then this rule won't work and I'll have to think of a different rule. That's my original reason for this thread. Bizarre, isn't it?