When it comes to ’90s TV, you might remember the familiar notes of your favorite theme song, the original series that have been rebooted since (or are soon to be), or maybe your favorite sitcoms. And it was on those comedies that we saw plenty of A-listers making some very memorable cameos. As TV Insider is launching the new Throwback section, we’re taking a look back at our favorites.

Who can forget Joe Namath on The Simpsons lecturing about caring for your car? Or RuPaul on Sabrina the Teenage Witch, insisting that the titular character (played by Melissa Joan Hart) needed to sign a release form while giving her a makeover? Kobe Bryant stopped by Sister, Sister to film a commercial, while Ray Charles got quite a bit of applause when he appeared on The Nanny.

Over on Friends, the friends got distracted when Billy Crystal and Robin Williams held quite the attention-grabbing discussion on the other end of the couch in Central Perk. Plus, on Seinfeld, George (Jason Alexander) got a bit too into his fantasy about Marisa Tomei.

Check out the video above to see where those and ones on Boy Meets World, Full House, Martin, and Smart Guy rank and to watch the fun clips!