KC Undercover to Mission: Impossible (1988)

Ernie and Judy from KC Undercover appear in the Halloween episode of Austin & Ally, "Scary Spirits & Spooky Stories"

Austin and Ally appear on an episode of Girl Meets World. Bringing the Disney Channel Live Action Universe into the Westphall Universe

Continuation of Boy Meets Wolrd

Sabrina the Teenage Witch also crossed over with Boy Meets World on several other occasions.

Sabrina from Sabrina the Teenage Witch visited Cher from Clueless in the episode "Mr. Wright."

Hakeem and Niecy from Moesha went to the prom with Cher and Sean from Clueless.

The Parkers was a spinoff of Moesha

The Hughleys crossed over with The Parkers.

The Drew Carey Show's Mimi appeared in an episode of The Hughleys

The Drew Carey Show did a cross over with Coach.

Newhart's Larry, Darryl and Darryl squatted in Coach's Hayden and Christine's home

The Bob Newhart Show's Bob Hartley woke up after dreaming the entire series Newhart during Newhart's finale.

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

St Elsewhere's Dr Turner was investigated for murder by Homicide's Pembleton and Bayliss.

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

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."

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

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

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.

Mission: Impossible was continued 22 years later