VIDEOS:
Frasier's Father
In Cheers, Frasier stated that his dad was a dead scientist, resulting in a retcon when he turned out to be a very-much-alive ex-cop in Frasier.
Example of:
Retcon
Flaming Moe's Cheers Intro
Example of:
Affectionate Parody
Sam & Diane
Example of:
Slap-Slap-Kiss
Kelly's Song
Example of:
Gift of Song