After premiering more than 20 years ago, Friends still lives on as one of the most trusted, binge-worthy shows we turn to anytime a long weekend looms on the horizon. And with its 10-year, 236-episode run, you can bet the storied sitcom racked up an impressive number of celebrity cameos along the way.
Some guests left an indelible mark (like Brad Pitt, George Clooney, Julia Roberts, and Reese Witherspoon, to name a few) while others may not spring to mind as quickly, plus a handful you may have missed entirely the first time around.
We're celebrating the Friends cast with a walk down memory lane. Dig out your favorite stretchy pants, get your popcorn ready, and revisit Monica, Chandler, and the rest of the gang, along with some of their most memorable famous guests.
Click through our gallery to see the best celebrity cameos to grace the set of Friends.
Brad Pitt
How could we forget Pitt (then married to Jennifer Aniston), who played Will, co-founder of "The I Hate Rachel Green Club"?
George Clooney and Noah Wyle
The worlds of mid-'90s NBC heavy hitters collided when ER stars Clooney and Wyle showed up—in scrubs!—as the cute doctors treating Rachel's ankle.
Julia Roberts
Roberts played Chandler's former classmate, Susie Moss (aka "Susie Underpants"), whom he humiliated in the fourth grade. Jean-Claude Van Damme also guest starred in the same episode.
Winona Ryder
Back in the early aughts, Winona Ryder made her appearance on the show as Melissa Warburton, Rachel's old college friend she kissed after a wild, sangria-fueled night of partying. Melissa pretended not to remember that encounter — until a kiss from Rachel to prove it happened elicits a long-held love confession.
Bruce Willis
Rachel dated Paul Stevens (Willis), the dad of a student Ross is seeing.
Anna Faris
Faris guest starred as the pregnant mother whose twins Monica and Chandler end up adopting.
Reese Witherspoon
Rachel's younger sister Jill (a baby-faced Witherspoon) comes into town and goes on a date with Ross.
Ben Stiller
Rachel's date Tommy (Stiller) CAN'T STOP SCREAMING.
Brooke Shields
Joey went on a date with Erika Ford (Shields), a fan who believed he was actually Dr. Drake Ramoray — and quickly revealed her stalker tendencies.
Susan Sarandon
Joey got a chance to rejoin Days of Our Lives when his comatose character receives the brain of castmate Jessica Lockhart (Sarandon), who he ends up sleeping with off-screen.
Aisha Tyler
Tyler played Charlie, a professor who starts off dating Joey before becoming the love interest of fellow paleontologist Ross.
Tom Selleck
The famous mustachioed Selleck played Monica's on-again, off-again boyfriend, Dr. Richard Burke.
Christine Taylor
Taylor played Bonnie, Ross's girlfriend, who shaves her head at Rachel's urging.
Dakota Fanning
Mackenzie (Fanning), the 8-year-old who is moving out of the house Monica and Chandler are buying, offers consolation to a saddened Joey.
Charlton Heston
The inimitable actor played himself, sharing his pearls of wisdom with Joey.
Kristin Davis
Rachel and Phoebe found the perfect girl for Joey in Erin (Davis), but he doesn't return her affections.
Billy Crystal and Robin Williams
The legendary comics cozied up on the famous Central Perk couch and shared a "private" conversation that had the rest of the friends all ears.
Sean Penn
Phoebe gave Ursula's fiancé Eric (Penn) the truth about her twin sister.
Helen Hunt
In another guest cameo by a fellow NBC star, Mad About You's Hunt played Jamie, a customer of Phoebe's twin sister Ursula, the always-confused waitress at their usual haunt.
Jon Favreau
Favreau played a recurring role as Monica's boyfriend Pete, a wealthy man with Ultimate Fighting Champion aspirations.
Charlie Sheen
Chicken pox ruined what otherwise would've been a romantic weekend for Phoebe and her old Navy flame, Ryan (Sheen).