Terrence and Phillip is TV show shown in South Park. Conversly, **South Park ** is shown on Canadian TV in the Terrence and Phillip episode of South Park.
“Doctor Who” as a television show exists in the Simpsons universe apparently, since Comic Book Guy was once seen with a wheelbarrow full of fast-food burritos stating “This should provide adequate sustenance for the upcoming Doctor Who marathon!” Also, when Sideshow Bob threatens to nuke Springfield - Tom Baker (in his Doctor Who garb) appears as one of the “esteemed representatives of television.” (Urkel is another representative). During the Halloween episode with Lucy Lawless, the Collector (Comic Book Guy) kidnaps Lucy, Tom Baker, Jeri Ryan & Matt Groening - so “Xena” and “Voyager” both exist in that universe as well.
On “All in the Family”: When Archie Bunker meets ‘Wheezy’ Jefferson for the first time, and is at a loss for what to talk about, he asks her if she watched the “Julia” show. She said no, and asked him if he watched “the Doris Day show” (which he did.) Also, Edith occasionally mentioned that her favorite soap opera was “Search for Tomorrow.”
On “Angel”, Angel once alludes to the Blue Man Group (who are on-again/off-again commercial ‘stars’) and says that ‘only two of them’ are demons.
Considering that Joss loves The Simpsons, I’m surprised I can only think of one Simpsons reference on Buffy: Willow once refers to herself as Cletus the Slack-Jawed Yokel when she doesn’t do as good as she’d hoped on the SATs.
Angel has at least one references to The X-Files, when in an early episode a cop calls Lockley “Scully”. She tells him that Scully’s the skeptic and that Mulder is the believer.
One the fake side, Queer as Folk occasionally mocked a TV show called “Gay as Blazes”, in which all the characters sit around reading Jane Austen all the time.
Speaking of X-Files, The 3 geeks had some **Star Trek ** paraphernalia in their lair.
On Home Improvement, **This Old House ** existed.
Judge Stone on **Night Court ** mentioned going to a Star Trek convention in an early episode and in a later episode there is a case involving Old Trekkie’s vs. Next Gen Trekkers.
On My Two Dads, they could distract Paul Riser’s character by telling him a good Star Trek Episode was on.
I think Star Trek has probably snuck into the most other shows, movies and books. It even snuck into The Running Man. Tom Clancy has made references to Star Trek, Charles DeLint, David Brin and many other younger Sci-Fi and Fantasy writers have.
Jim
But… but… no… that can’t be because you see… you see… Dianne Wiest plays Nora Lewin on L&O, which means that if Dianne Wiest is an actress then there was no Nora and there’d be nobody to really serve as D A AND MY BRAIN HURTSSSS…
It’s not as bad as all that; I just didn’t know Weist’s character’s name.
Other Simpsons ones include broadcasts by Major League Baseball and Joe Millionaire.
Ah, thank goodness. For a second (or was it an eternity?) all was chaos.
In one episode of SANFORD & SON, Fred entered a Redd Foxx lookalike contest. The alternate Redd Foxx was a movie star. While I know that Foxx was a big name in the comedy circuit, it wasn’t until S&S that he was really huge and known to everybody, so it irked me- it’d be like Chandler Bing entering a Matthew Perry lookalike contest. Also, the fact that Fred Sanford was named for Redd Foxx’s brother… another time you just start seeing the vortex open.
Arnold the Pig on Green Acres watched Gunsmoke on one episode (I think they just had audio of gunshots rather than actual video clips). Rudy on The Cosby Show loved The Tonight Show when she was allowed to stay up late on one episode, and Baywatch had an odd episode in which Gilligan’s Island was both a TV show and a dream sequence.
On a Mad About You episode John Astin portrayed a new neighbor who might or might not have been John Astin (Paul & Jamie debated whether or not he was) and The Addams Family was referenced.
Other Simpsons: Twin Peaks and the 1984 Summer Olympics. Tom Brokaw exists, so by extension NBC Nightly News does too. Luke Perry exists so presumably 90210 exists (90210 also exists on Family Guy).
Much to the kids’ dismay, The Simpsons is very popular in the South Park universe.
In 24, Fox News clearly exists, just in case the viewers might forget what channel they were watching. grumble grumble
Which reminds me that Saved By the Bell exists in the Mad About You-niverse. Jamie comments that it’s strange for Paul to watch the show, and he replies that the networks air so often, he feels guilty for not watching it.
One of the characters on Bones spends time watching DVDs of Firefly
In the movie, as I remember, you can see a bit of one of Max Fleischer’s Superman shorts on one of his screens.
Roseanne also referenced the OJ trial, with Marcia Clark (okay, Laurie Metcalf doing a great Marcia Clark) climbed out of Roseanne’s television (I consider the OJ trial and very long running TV show).
Charles in Charge talked about Happy Days and the kid who said “woah, woah, woah.” This I remember, but I don’t remember to wear gloves outside.
On “Ned and Stacy”, Ned was quite upset with the cancellation of “Mr. Belvedere”.
I saw an episode of Family Guy recently where Brian was watching “One Day at a Time”.
In “My Name Is Earl” Puff ‘N’ Stuff has been shown a few times and several other clips of shows I don’t recall.
Jim
The 60s Batman series exists in the Simpsons-verse, including at least one episode that doesn’t exist in ours (featuring Krusty as special guest villain Clownface). Adam West exists in the Family Guy-verse but it’s a little fuzzy as to whether the Batman series also does.
Cliff Clavin from Cheers went on Jeopardy.
Sesame Street exists in The West Wing universe. Elmo the Muppet filmed some spots with Mrs. Bartlett and the staff teased C.J. that she was related to Big Bird.
Does 24 parody Fox News the way The Simpsons did (nearly getting itself sued by Fox, depending who you listen to)?
“Oil found to keep seals soft, supple.” 
And I have to say, you people are the best. I’m way too amused by things like this. 
Thom Holbrook needs an editor.