When TV shows "guest star" on other TV shows

But, George ans Susan used to watch Mad About You together. That kind of messes up the continuity.

As for Kramer being Murphy Brown’s secretary, it was an acting gig, and no one ever made the statement that Murphy Brown was a real person like in the OP.

Ah, but Kramer was an actor on the Murphy Brown set playing her secretary.

The character Kramer was not Murphy’s secretary.

Laverne and Shirley spun off from Happy Days, with one or two visits from the Fonz. (And the short lived Joany loves Chachi… heh.)

Three’s Company had a spin off, The Ropers.

I missed that one completely, a quick google says it was aired at the start of May (on the second) which is a night I don’t even watch TV anymore, besides Cold Case is on Sundays here. But then, when I think of crossovers the first that comes to mind is the Pretender/Profiler crossover that was 2 hours long (on Pretender, then Profiler). I don’t watch CSI: NY (never got into it, and I haven’t watched the original in awhile), but if it had been advertised I might have just for that.

There are some dimly-remembered Hanna Barbera crossovers, like Scooby Doo meeting Batman and the Addams Family. Fred Flintstone and Barney Rubble shared a show with Ben Grimm, the Thing, but I forget if they actually met or not

ABC once had a Las Vegas night. Characters from the 4 sitcoms airing on Wednesday night (Coach, Drew Carey, Grace Under Fire and Ellen) went to Las Vegas and would run into each other during the course of the shows.

[Maxwell Smart]
Missed it by that much.
[/Smart]

On SCTV, Bobby Bittman would guest on the Sammy Maudlin show. The next week Sammy Maudlin would guest on the Bobby Bittman Show.

Never a shortage of guests with that kind of arrangement.

On the 1960s, live action Batman series, a recurring gag had Batman & Robin scaling a wall to sneak into the villain-of-the-week’s lair. As they were working their way up there, a window would open, a minor celebrity of the day would stick his head out the window and briefly chat with the dynamic duo. On one occasion, Lurch from the Addams Family was the minor celebrity who stuck his head out the window.

And once they ran into the Green Hornet and Kato.

On NBC Thursday night years back there were several shows all set in NYC (Friends, Sienfeld, Mad About You?) and they had a power outage that happened in all three show. I’m guessing that Kramer caused it.

Frank Black from Millennium on The X-Files.

It was revealed that John Munch and Lenny Briscoe had an ex-wife in common.

In the episode where **Roseanne **had breast reduction surgery, she had a dream while coming out of anaesthesia that Doogie Howser was the doctor who performed the operation. That was pretty darn funny.

I’ve been seeing too many of these lately. The most annoying one was a recent Medium which spent far too long in a dream sequence where the main character is a contestant on Deal or No Deal.

It’s such blatant “product placement” with no upside for the audience. You can tell the writers were ordered to put it in and had to strain to come up with any reason at all for that sequence to be there.

Funny, I hardly ever watched “Seinfeld” and could have sworn he was on the actual show.

Either way, it’s not listed.

There was an episode where several characters from Las Vegas showed up in Crossing Jordon. I think they did a reverse episode (with the Crossing Jordon folks on Las Vegas later in the season too.

“The last five minutes of St. Elsewhere is the only television show, ever. Everything else is a daydream.”- Dwayne McDuffie

Actually IIRC Jamie caused it while trying to disconnect an illegal cable hookup.

I knew you really meant to say Elliot Carlin appeared in St. Elsewhere, right?

Hank, Peggy, and Bobby Hill made a cameo appearance in The Simpsons.

The episode of South Park, “Summer Sucks,” features Dr. Katz as Mr. Garrison’s therapist.