Oooh, I got one *raises hand*
Match Game-Hollywood Squares Hour: the conversion of the Match Game panelists set to the Hollywood Squares set by adding the third tier. ETA: already mentioned, but still makes for a really cool transition of a show that had mediocre execution.
Also, the Match Game contestant podiums sliding off set once the game was done (and the Hollywood Squares podiums sliding into place, though that was rarely, if ever seen).
