As Friends’ popularity grew and grew in the 1990s, so did its pulling power for A-list cameos. During its 10 years on the air, an impressive list of celebs made guest appearances in Friends, some of which are very well-remembered. Billy Crystal and Robin Williams’s irreverent appearance in Central Perk springs immediately to mind, while others are often forgotten (who else still gets a surprise every time Charlie Sheen pops up when you’re watching Friends repeats or re-streaming on Netflix?). As the show celebrates its 25th anniversary, we’re putting your Friends knowledge to the test, and seeing how many of the show’s most famous guest spots you can still name from memory...
Friends Characters We Wish We'd Seen More Of, As The Hit Show Turns 25 Which Friends Episode Is Really The Best, As The Show Turns 25? 25 Years Of Friends | Good Vibes Only 8 WTF Moments The Cast Of Friends Have Experienced Since The Beloved Show Finished Jack and Judy Geller (Elliott Gould and Christina Pickles)
Whether they're being wildly sexually inappropriate, insensitive to their daughter or putting everybody in their place, the arrival of Monica and Ross's parents always guarantees an eventful episode.
While Jack and Judy are the recurring characters with the most guest appearances (20, if you're interested), we'd still like to have seen them a little more often. More Susan Bunch (Jessica Hecht)
Sadly, Susan was never seen past the sixth series of Friends, which is a real shame as we loved her long-standing frosty relationship with Ross.
We particularly enjoyed her blasé putdowns, which she managed to deliver with an iciness we aspire to. More Bonnie (Christine Taylor)
A woman who will shave her head in the middle of a beach holiday just because someone planted the mere suggestion in her mind. Amazing.
We know Rachel wouldn't have been thrilled by the prospect, but we definitely wouldn't have minded Bonnie sticking around for more than two episodes. More Eddie Menuek (Adam Goldberg)
As Chandler's brief time living with Eddie grew to a close, he became an even more odd creation, but it would have been great if the writers had cranked things up another notch with his strangeness, or at the very least showed us what happened when he was shown the door.
Where did he go? Who does he live with now? How is his cherished pet, the goldfish cracker? These are the questions we need answers to. More Story continues Amy Greene (Christina Applegate)
It's always great when one of the characters' family members arrive, because they remind you of how they used to be – and that's never more true than when Rachel's sister Amy arrives on the scene.
Amy is even more spoilt, and cares less about other people's feelings, than Season One Rachel, though with slightly less iconic hair. (No offence to Christina Applegate, of course). More Frank Buffay Jr and Alice Knight Buffay (Giovanni Ribisi and Debra Jo Rupp)
Joey was the character who went on to end up with his own spin-off, but we think it definitely should have been Frank and Alice.
Who honestly wouldn't want to watch a show about a man who marries his home-economics teacher, then raises triplets – that his sister gives birth to – with her? It would have been an Emmys shoo-in. More Amanda Buffamonteezi (Jennifer Coolidge)
Phoebe and Monica made the unwise decision to "cut out" Amanda, but frankly we'd have happily seen her stay until the finale, for the dancing alone.
More Mr Heckles (Larry Hankin)
The great thing about Mr Heckles, especially watching earlier series back, is that it reminds you just how young the characters were – and what a nightmare that group of twenty-somethings would have been if you lived near them...
More Erica (Anna Faris)
...conversely, by the time Erica arrives in the tenth season, her youthful naivety proves just how far the six principal characters have come.
We can't help but feel the fabulous and funny Anna Faris was criminally underused, and it would have been nice to see her stay around exploring New York for a while longer, rather than her few fleeting appearances. More Gunther (James Michael Tyler)
True, Gunther did feature in quite a lot of episodes, but how much do we know about the man behind the fluorescent hair? What does he do at night? Where does he live? What are his hopes? His dreams? His fears? Actually, it's probably best not to know...
More Marcel (Katie the Monkey) Love HuffPost? Become a founding member of HuffPost Plus today. This article originally appeared on HuffPost.