The Next Karate Kid (1994) was the fourth Karate Kid movie and the title character was played by a relatively unknown young actress, Hilary Swank (now a 2-time Oscar winner).
Yeah, it’s also kind of weird seeing Agent Smith as one of the other drag queens!
Which reminded me of this one:
Erika Eleniak, the stripper in the cake from the original Under Siege, was the girl who Elliot kissed in E.T.
I bet hajario is confusing Roseanne with the first season of The Real World.
Speaking of Roseanne, I watched that show for years before I noticed that Fred (Michael O’Keefe) was Danny Noonan from Caddyshack.
I also notice that the girl from Panic Room was just in some vampire movie.
Random ones off the top of my head:
I actually saw Jean-Claude Van Damme in his first role at the drive-in…he was the bad guy in No Retreat, No Surrender #1.
I recently saw a rerun of Death Wish II, and Lawrence Fishburne was one of the members of the street gang that terrorized Bronson’s family.
I’m still shocked that Janet Jackson was on Good Times.
If possible, you should see Sarah Jessica Parker on the short lived Square Pegs.
I was also surprised to see that the Rundown featured a very grown up Ernie Reyes Jr., who was a popular child action star in 80’s movies like TMNT and the Last Dragon. Apparently, he had a role in Rush Hour 2 too, but I must have missed it.
Oh, I got one. Another one from Roseanne: It actually took me a little while to realize that David (Johnny Galecki) is later Leonard from The Big Bang Theory. Even when I saw Darlene (Sara Gilbert) as as then-girlfriend Leslie, I didn’t think about it.
If that’s not right under my nose, I don’t know what is.
Of course! Big lightbulb!
Other Roseanne alumni - George Clooney as Booker, Glenn Quinn as Mark Healy who became Doyle on Angel, Joseph Gordon-Levitt as George, and the list just goes on and on. If you don’t have Roseanne on your acting resume, it looks like you weren’t really trying. 
Feb. 8, 2005, from the Wikipedia article on McCallum:
This is one of my two favorite inside jokes from TV series, along wth Ray Walston As the judge on Picket Fences scoffing at reports of men from Mars during a flying-saucer scare.
I should Pit you for insinuating that I watch The Real World! I remember reading about it at the time but my memory is obviously faulty because I can find no evidence of it using Google. My apologies.
Some years ago I happened to catch Fast Times At Ridgemont High. There’s a blink-and-you-miss-it scene of some random high school assholes dashing through the scene and raising hell, and then another scene at a dance, when you see one of them dancing in the background. I said to myself, “Is that?..why, yes, that is a very young and fully-haired pre-Top Gunand ER Anthony Edwards!”
Little weird.
Also, the publicist in This Is Spinal Tap, who complains about the sexism of the band’s cover? Fran Drescher.
IIRC, she actually reprised that role (Bobbi Flekman) in an episode of The Nanny.
The most recent one for me was figuring out that Slater, the stoner dude from Dazed and Confused, went on to play Tim Speedle on CSI: Miami.
(There’s a ton of people in Dazed and Confused, but I already knew about all the others. Yes, including Renee Zellweger’s non-speaking uncredited role as an extra :))
Earlier this week, my daughter and I were watching Pulp Fiction when we recognized Kathy Griffin in a small speaking role.
Look for a huge fluffy head of red hair.
I remembered this apparently in the wrong time frame but in 1996 there were network ads for a new sitcom that seemed to revolve a young black guy and a young white guy. I noticed just because the black guy was also named Dave, like ME!. I never saw the show, but when The Dave Chappelle Show became famous, I thought, “It’s that guy from that total flop!” It must have been “Buddies” Buddies (TV Series 1996– ) - IMDb.
Actually, I think this is opposite of the OP. But now I’ve typed it all, so here you go.
She was also one of Buffy’s stuck up friends in Buffy the Vampire Slayer (the movie, not the series).
She did a Comedy Central commercial where she re-enacted her role in Pulp Fiction. I remember her more from that commercial than the movie.
Do you have a link to the commercial? I’d like to see it.
She was dating Quentin Tarantino when he directed that movie, right?
Going back a looooooong ways, a Three Stooges one-reeler Three Little Pigskins features a blonde (yes, blonde) bombshell played by a then-unknown actress named…Lucille Ball!
Unfortunately I can’t find it but some Comedy Central ads from about the same time are on youtube so someone might upload it at some point. I think it was around 1996 or so.
It was basically edited into little blips so she re-enacts her 1 minute scene in like 10 seconds, complete with a little shriek and pretending to run away. It was kind of amusing.
I’ve heard that but I don’t think I have heard either of them mention it anywhere. They seem like kind of an odd couple but I have seen stranger so it wouldn’t really surprise me.
Tony Shalhoub is an actor I never noticed until Monk but I was shocked when I checked IMDB and saw how many things I had seen with him, the shadow guy episode of X Files, Men in Black, Galaxy Quest, Gattaca…
Speaking of Gattaca, you really can’t recognize her because she is wearing a surgical mask but Maya Rudolph of Saturday Night Live plays a delivery room nurse.
Unless it was the drugs, I vaguely remember Quentin Tarantino as an Elvis impersonator on The Golden Girls.