Oddest/ most interesting connection to a role featured on a different show

There were plenty of Firefly references - 10 "Firefly" References On "Castle" That You May Have Missed

Two stick in my mind and both touch on James Garner. I used to get a kick out of when Jim Rockford would climb into a Maverick to escape or chase someone…It wasn’t a regular occurrence, but it did happen. The other was when he was playing Grandpa on “Eight Rules…” and he would make some reference to wanting to get home to watch reruns of the Rockford Files.
For that matter, I seem to remember “Eight rules…” doing a dream sequence with John Ritter and Three’s Company…

Courteney Cox did a 3-episode guest stint on Scrubs. Ken Jenkins, who starred as Dr. Kelso on Scrubs, plays Cox’s father on Cougar Town.
In an episode of Cougar Town, Jules (Cox) and her dad met the actual character Ted from Scrubs, played by Sam Lloyd, who was spooked by how much they looked like the mean doctors he used to work with. Later in the episode, or maybe a different episode, a bunch of actors from Scrubs, including Zach Braff as a pizza delivery guy, showed up in brief cameos, freaking Ted out even further.

St. Elsewhere had all sorts of weird casting notes and shoutouts. The character of Coolidge was actually from the earlier series White Shadow. In one episode Coolidge saw who he thought was a fellow graduate of Carver High School, played by Shadow’s Timothy Van Patten. In another, five members of the old Steve Allen Show showed up as the parents of various doctors.

Peter O’ Toole playing Henry II in two very different films should count.

Seemingly for no reason whatsoever, Burgess Meredith played The Penguin on an episode of The Monkees.
No dialog, no screentime with any other characters. He’s just present at a banquet or something. As the main action is happening there are occasional cutaways to him laughing his Penguin laugh.
On the topic of 60s Batman, surely there are some examples among the “window cameos” that frequently happened whenever Batman and Robin were scaling the outside of a building. Do we have any 60s Batman experts here?

Being pedantic, I’m not sure that counts as lampshading.

In one episode Howard bought the building Floyd’s shop was in and immediately hiked the rent. They got in a big fight and Floyd left town. Andy helped them compromise, Floyd came back and all was well.

In Arrested Development, one character refers to Michael Bluth derisively as “Opie.” The narrator, Ron Howard, says that she “had gone too far and she had best watch her mouth.”

When someone mentions Andy Griffith, Howard makes sure to indicate that they respect him too much to make fun of him.

And, of course, there was Barry Zuckerkorn (Henry Winkler) jumping over a shark . . .
More here.

Ben Vereen as E. L. “Tenspeed” Turner was one of the lead characters of Tenspeed and Brown Shoe in 1980. He returned to that role in the series J. J. Starbuck in 1988 when the lead character suddenly acquired a partner. His character was only written into the series because the main character J. J. Starbuck (Dale Robertson) was hurt in an accident (as was Robertson in real life) and it wouldn’t have made sense for him to do some of the things he did in the series alone.

AD also had a few episodes in which the family tire of Zuckerkorn’s (Winkler) incompetence and hire a new family lawyer - played by Scott Baio (who played Chachi on Happy Days.)

On a episode of the 1960s British spy parody series the Avengers - “Death at Bargain Prices” - Emma Peel goes undercover as a sales clerk in a department store. Scenes in the toy department show Dalek action figures (from Doctor Who) for sale at the counter.

I’d say the oddest/most famous one is Werner Klemperer as Col. Klink.

How has no one mentioned the good time had by all when David Duchovny appeared on The Larry Sanders Show leading to Garry Shandling’s appearance on The X-Files yet?

Garry Shandling Do you dress on the right or the left?
Fox Mulder Wh… huh… what do you…
Garry Shandling Look, I play a character, I need to find his rudder, his center…
Fox Mulder I guess mostly to the left.
Garry Shandling Mostly?!?!

There was the Community/Cougar Town crossover. Abed on Community mentioned getting a role as an extra on Cougar Town but having to bolt due to a bathroom emergency. He was later show in an episode of Cougar Town being the world’s worst extra, ending with him hurrying away in the background.

Kramer was Murphy Brown’s secretary in a Seinfeld episode.

Neil Patrick Harris (as Doogie Howser) on the episode of Roseanne where she has breast reduction surgery.

Paul Buchman finally got rid of his bachelor apartment in one episode of Mad About You. At the very end, he goes to the apartment to talk to the guy he’s been subletting it to: Cosmo Kramer of Seinfeld. And of course the waitress at Paul and Jamie’s favorite restaurant is Ursula Buffay, twin sister of Friend’s Phoebe.

Going back to the days of shoulder pads and big hair, an episode of Remington Steele guest-starred Tom Baker. I remember that vividly, because at the time, Doctor Who, at least in America, was an obscure British sci-fi show that aired at 10 o’clock on PBS. Someone at *Remington Steele *must have been a fan, though, because in the episode Baker wore a trench coat and a long striped scarf.

Jaime and her best friend Fran once went into Central Perk and had an encounter with Phoebe, thinking she was Ursula the waitress.

Who also appeared on The Simpsons as an authority figure for Homer.

Conan O’Brien tried to get Klemperer to reprise the role for his show, but he had no interest, though did tell them he was a big fan of the show.

OTOH, Conan’s contest to find/salute to Whitman Mayo’s Grady was a thing of beauty and a perfect coda to Mayo’s career. I can’t quickly google it, unfortunately, but I’m sure it’s on the net somewhere.

On The Big Bang Theory, there was an episode where they were trying to find a replacement for their trivia team, and Raj suggested they use the girl from “Blossom” b/c she had a PhD in Neuroscience. Mayim Bialik, who does have that PhD, was Amy Farrah Fowler on the show. (I can’t remember whether she was already a cast member or not when Raj said that)