Twin Peaks to Wonder Woman

Fringe's Walter is friends with Dr. Jacoby from Twin Peaks

In the pilot of Person of Interest John Reese's suspect Diane Hanson has emails numerous characters from Fringe

In the pilot of POI numbers 4-8-15-16-23-42 appear as the time stamp of a surveillance camera, the same numbers won Hurley the lottery on Lost

The airplane that crashed and strand the cast of Lost was Oceanic Airlines Flight 815 also featured on Diagnosis Murder.

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

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

Here's Lucy's Mary Jane Lewis was originally a character on The Lucy Show (also called The Lucille Ball Show).

Mr. Mooney from The Lucy Show was on Hi Honey, I'm Home!

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

Lou Grant spun off of The Mary Tyler Moore Show

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