Hart to Hart to Jake and the Fatman

Moonlighting's Maddie has a Christmas Carol style dream where her firm is bought by the Hart Detective Agency of Hart to Hart

Lou Grant centered around Lou as editor of the fictional Los Angeles Tribune which has been featured on Moonlighting

Lou Grant spun off of The Mary Tyler Moore Show

The Mary Tyler Moore Show's Georgette Baxter crossed over onto Hi Honey, I'm Home!

Alice & Trixie from The Honeymooners crossed over onto Hi Honey, I'm Home!

Here's Lucy's Lucy was driven around Miami by Ralph Cramden of The Hooneymooner's

Here's Lucy's Lucy Carter and Mannix's Mannix are held hostage in an episode of Here's Lucy.

Mannix returned to TV on an episode of Diagnosis Murder to solve an old unsolved case with the help of Dr Mark Sloan.

Diagnosis Murder was a spinoff of Jake and the Fatman.