This is mainly a joke on the modern Major General song of Gilbert & Sullivan, but has some Cats too. I love this one!

This cartoon is from Catena Manor, thanks Nemi!

This one's an Off the Mark cartoon Offthemark.com.

This is from a comic strip called Zits. I found this on a website but I can't remember which one!!

The kid in this Grand Avenue strip has a CATS poster on his wall! Also, there's one from Les Miserables. Maybe he likes musicals??

This was posted on the Musicals.net forums ages ago. I'm not sure where it's from.

MOVIES

On an episode of the TV show Alf, a man (don't know his name) says he's going to go see a musical. Alf then talks about how he hates musicals, but when the man says he's seeing CATS, Alf then brightens up and wants to go because "after the show he can go backstage and eat the actors". See it on Youtube
--Celaeno

In the TV show 7th Heaven this man Carlos comes to stay with his family and he's from New York. One of the sons, Simon, asks him about four times if he saw CATS on Broadway in New York, and he says he didn't, so then he keeps bringing it up and telling him about the show.
--Nedame

In Caroline in the City the best friend of the main girl is in Cats. Occasionaly she'll be in costume for a bit in some episoides.
--Atraielees and Drumdraper

The Muppets did a parody on Muppets Tonight. Jason Alexander was the guest on the show. Apparently he and Gonzo went to college together and wanted to do a show called Bats that never took off.
--Drumdraper

In Pinky & The Brain, they had Albert Floyd Webster and Pussy Cats! Pinky made a musical: Mice, The Musical, and the numbers within sounded a lot like Jellicle Songs for Jellicle Cats and Memory! The episode was called Broadway Malady, you can see it on YouTube!
--The Hidden Paw

In American Dad, the alien (forgot his name) and the daughter Hayley agreed she could keep a bunch of monkeys in the basement. He said "Well, theatre/sanctuary. By the end of the month we'll have the best all-monkey production of CATS you've ever seen!"
--Bombalur1na

In the TV show Full House Joey was saying how he had a friend that played in CATS and he could borrow a costume from him.
--Jem

Also from Full House, Rebecca and Jesse's child counselor tells them to notice the individual interests in their twin boys. He said one of them may like science, while the other likes music, so take one to the museum and the other to see CATS!
--Celaeno

On the TV show The Nanny they are constantly referencing Cats. The story is the guy she works for, I forget his name, had a chance to be a producer or something for the show, but he thought it was a stupid idea and missed out on the chance.
--Sleeping Tiger

In the television show, Hey Arnold, Helga's father takes her to see "Rats" on Broadway, an obvious rip-off of our favorite show!
--Alex

On the TV show Family Guy, Peter is having a flash back to when he saw the musical Cats. A few memorable cats (Mistoffelees, Munkustrap, Skimbleshanks, etc.) are dancing when Peter drives his car onto the stage and accidently hits Munkustrap. He then tries to convince the audience that Munkustrap 'jumped out in front of him'.
-- Amaris

On Friends, the episode called, The One With the Fake Monica, the fake Monica tells the real one that they should audition for a Broadway show, sing "Memory" and make complete fools of themselves.
--From Lillypaw

In The Simpsons, Bart and Milhouse get 'high' off of extra-syrupy Squishees, and go to see CATS. During the show, Bart shoots a spitball at one of the characters! See it on Youtube
--Alex, video from Celaeno

On The Simpsons, the family was watching an episode of Itchy and Scratchy, and the cat goes to see Cats, and they show one of the cats, Rum Tum Tugger, but instead, he was blue and called Tim Tom Tagger. See it on Youtube
--From Lillypaw, video from Celaeno