Columbo to Eli Stone

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

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.

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

Charlie from Lost was in a band named Driveshaft. Alias? Sydney threw a party and the music playing at the party was Driveshaft song. Additionally Alias also mentions Oceanic Airlines and so it has crossed with both Lost directly and also all the shows which mention Oceanic.

The Credit Dauphine Bank from Alias also exists on Eli Stone