You’ve stumped me… Nuts?
Here’s one. From L.A. Story, when the camera swoops around the large, outdoors circular table at the restaurant when the gang is doing brunch, and the waiter is taking orders, and everyone’s ordering a uniquely fussy cup of coffee: if only it could have ended on Richard E. Grant, ordering “cake and fine wine”.
Nope . . . think 70’s television. A trip to IMDb should fix you up if that clue doesn’t do it for you.
I keep hoping Rowan Atkinson will turn up as a patient on House . Or at least Stephen Fry.
Got it. A list of TV shows that I’ve never watched would stretch from New Jersey to, oh, San Francisco… 
Pepper Mill lamented that in the first episode of Star Trek: Enterprise, the first time they get the Transporter to work and save the captain’s sorry butt, Scott Bakula should have said, in a world-weary way, “Oh, boy!”
In The West Wing, Michael Douglas should have played an former president and made reference to when Bartlett was his chief of staff.
When Arnold Schwarzeneggar pooh-poohed Rambo’s physique in TWINS, I was disappointed when Sylvester Stallone didn’t return the favor to the Terminator in COPLAND or some other movie.
I am always disappointed when superhero movies don’t allude to other superheroes. I’d have loved it if Ben Urich covered Dr. Otto Octavius’ press conference in SPIDER-MAN 2 or if the Bugle had headlines about The Hulk or The X-Men or even Daredevil, or if Hugh Jackman had a cameo. Or maybe even something like this exchange:
Mary Jane: Look, Peter! It’s the Avengers!
Peter Parker: Where?
Mary Jane: Right here in this window display. Oh, I’d kill to play Emma Peel.
Probably copyright crap, Askia. On the small screen Ma Kent makes a reference to “that nut in Gotham” in the animated Superman and on Smallville an obscured headline has the word “Thermescyrian” [sic] in it. But those are in-jokes that were made and therefore off-topic.