Hanging In to The King Of Queens

Hanging In (and Maude's) Maggie Gallagher crossed over onto Soap for 10 episode

The first All in the Family spinoff character was Maude. Maude was Edith Bunker's cousin.

The Jeffersons' George Jefferson was the second All in the Family supporting character to spinoff onto his own show.

George Jefferson gets help from Barney Collier from Mission Impossible

Mission: Impossible was continued 22 years later

Diagnosis Murder's Doctor Jesse Travis's father is a spy that someone is trying to kill. One of the possible suspects is the original Mission: Impossible's Cinnamon Carter.

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

In an episode of Veronica Mars, Veronica's fortune cookie had the numbers that won Hurley from Lost the lottery.

The mugshot of Malcolm T Wiggins from the X-Files episode "Titonus" appears on the wall of a police interrogation room in the Veronica Mars episode "Leave it to Beaver." Also the fictional car rental company Lariat where Mulder & Scully always rented their cars was featured prominently on the Veronica Mars episode "Rat Saw God."

Homicide's John Munch questioned The X-Files' The Lone Gunmen.

Homicide's detectives watched Oz's Miss Sally on TV.

St Elsewhere's hospital management company Weigert (was Ecumena) took over Oz's hospital.

The Bob Newhart Show's Elliot Carlin visited the psych ward at St Elsewhere's St Eligius Hospital.

The Bob Newhart Show's Carol was Murphy Brown's secretary for an episode.

High Society and Murphy Brown crossed over during a network crossover night

High Society and The Nanny crossovered during a network crossover theme night

The Nanny's Fran Fine and Everybody Loves Raymond's Raymond Barone went to high school together

The King of Queens and Everybody Loves Raymond crossed over on a network crossover night.