Benson to Medium

Soap's Benson DuBois spunoff on to his own show, Benson

Maggie Gallagher from Hanging In crossed over onto Soap

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.

An episode of Crossing Jordan featured a priest from St. Eligius Church in Boston. St. Elsewhere was set at St Eligius Hospital in Boston

Las Vegas' Danny McCoy and Sam Marquez took a plane to Boston. While in flight a guy on the plane died causing a crossover with Crossing Jordan.

Characters from Medium visited the Monticito Casino from Las Vegas