After watching Wrath of Khan in the theater years ago, I turned on the TV at home and found the old Start Trek episode Space Seed was on. I’d never seen it, even though I was a huge trekkie.
A small coincidence from last night.
My wife was watching an episode of The Love Boat while I was watching an episode of The Jeffersons.
One of the guest stars on The Love Boat was Sherman Hemsley. And George Jefferson made a joke about “taking the Love Boat to Fantasy Island”.
Back in the 70s, I once (OK, many times, but only one that’s relevant) spent an entire evening in front of the TV. Five shows, and three of them had one-off characters named Millard on them that night.
Not as interesting as some of the examples given here. But I remember once watching an episode of Law and Order and there was a commercial break. One of the actresses in the commercial was also guest starring in the Law and Order episode. She had just been in a scene before they cut to the commercials.
I’d be more afraid that Columbo would end up folded into a suitcase and dumped in a toxic landfill. I don’t suspect he’s very good at hand-to-hand combat.
Obviously a mid-century cloning project that was hushed up. 
I started a thread like this nearly 20 years ago but it didn’t go anywhere.
In the movie Dead Men Don’t Wear Plaid Steve Martin’s character was named Rigby to take advantage of the fact that so many film noir movies had a character named Rigby in them.
The other day I was watching an old episode of Warehouse 13, which is free with ads on IMDB’s streaming service. On the show, a nun was hypnotized into believing she could fly. She climbed up to the top of the church’s bell tower, proclaimed “I can fly!”, and then the show cut to commercial… and the commercial happened to feature the song “Come Fly With Me”.
I was also watching something recently in which a character said something like “You never know when a virus will jump from bats to humans”, which aired years before the pandemic. Unfortunately now I can’t remember what it was. Maybe Silicon Valley.
End of February/beginning of March 2020, just as the pandemic was really taking off, I’m watching an episode of Match Game from the '70s. For once, Gene Rayburn doesn’t kiss a contestant, saying “I just got back from China. They have some weird viruses over there!” 
The last story of a segment of a newscast in Cleveland Ohio was about capital punishment. The first commercial of the following commercial break was for new brand of frozen pizza. It began, “What would like on your Tombstone?”
You sure it was a TV show? Because the movie Contagion talks about that, and in fact shows the bat - pig - human tracking.
Yeah, I’m sure, mainly because I haven’t seen the movie Contagion.
Actually, the scene has come back to me now, and I am certain it was Silicon Valley. The main character is at his doctor’s office for an STD test. The doctor expresses shock that he actually needs an STD test, and makes a comment like “There are bigger things to worry about, like you never know when I virus will jump from bats to humans.”
Not a killer coincidence, but…
I watched two recorded episodes of Jeopardy! the other day, one current, one a year old. Both had clues whose questions were “The Good Earth”.
Already mentioned in another thread: The other day, I had the TV tuned to an episode of Hawaii Five-O (the original, not today’s pale imitation) as I was working on the computer. While I was typing the words “wasted time,” Steve McGarrett told Danny Williams not to “waste time” following certain leads.
I was making an online payment this evening, and the website asked for my “CVV.” I was unfamiliar with the term—I’d always seen/heard it called a “three-digit security code.”
Half an hour later, I was watching Jeopardy! There was a question about credit card CVVs. (“Credit Verification Values”?)
Watching Funny You Should Ask! this afternoon, I learned that the state of Kentucky has twice as many barrels of Bourbon than it does inhabitants.
The same thing was revealed on Jeopardy! a few minutes ago.
Not exactly a coincidence, but something cool : decades ago, I was watching an “all-new” episode of Fantasy Island in which Jack the Ripper realises he’s slipped forward in time when he sees the date on Roarke’s desk calendar… which was the date I was watching it. IMDB confirms it in the Trivia section : November 29, 1980. Of course, it was probably possible for the writers to know in advance when it would air, or maybe somebody at ABC shuffled up the broadcast order so that this date would match.
The first is highly unlikely (scripts are not churned out on a regular schedule, only when the final rewrite is finished, and that can take a long time). The second, only less so, since no one really cares much as long as the show is in the can.
My latest entry: Last week, I watched an episode of Matlock in which the perp put a body in a sauna to create a fake time of death.
Last night, I watched an episode of Death in Paradise in which the perp put a body in a sauna to create a fake time of death.
Well, to be fair, who doesn’t do this once or twice a week???