With a total of ten years on the air and a reputation as one of TV's most-watched sitcoms, Friends racked up an impressive number of high-profile guest stars in its time. However, the show's final 236-episode tally also makes those famous faces a little tough to keep track of. So, in the spirit of Friends' 20th anniversary, we plumbed the murky depths of IMDb and returned victorious with our picks for the top 73 appearances — from surprise one-off spots (Julia Roberts as "Susie Underpants") to beloved season-spanners (hello, Tom Selleck's glorious mustache), celebrity cameos (Jean-Claude "The Muscles from Brussels" Van Damme), and plenty of "before they were famous" revelations (Rebecca Romijn's first-ever credit, Parenthood's Mae Whitman in single digits, a pre-Sex and the City Kristin Davis — the list goes on).

It's enough to drive you six-degrees-of-Kevin-Bacon-style crazy. Like, what do you make of the fact that both the Dean from Community the principal from Glee rocked nameless few-line roles on the same show before hitting it big? Or Jane "Sue Sylvester" Lynch, for that matter — along with most of her Christopher Guest mockumentary co-stars, Bob Balaban, Michael McKean, Jennifer Coolidge, Fred Willard, and Harry Shearer? Then, there's Shearer's fellow Simpsons multi-vocalist Hank Azaria — and how about 30 Rock-ers Chris Parnell and Scott Adsit?

Indulge your inner casting fanatic with a skim of the list below.

CHARLIE SHEEN

... as Ryan, Phoebe's onetime Navy paramour to whom she gives Chicken Pox.

("The One with the Chicken Pox," S2E23)

Danny DeVito

... as Roy, the stripper at Phoebe's bachelorette party.

("The One Where the Stripper Cries," S10E11)

Susan Sarandon

... as Jessica Lockhart, Joey's Days of Our Lives costar.

("The One with Joey's New Brain," S7E15)

Sean Penn

... as Eric, Phoebe's twin sister's fiancé.

(2 episodes, S8E6-7)

Hugh Laurie

... as "The Gentleman on the Plane" who has a tiff with Rachel.

("The One with Ross's Wedding: Part 2," S4E24)

Ben Stiller

... as Tommy, AKA the "Screamer," Rachel's boyfriend.

("The One with the Screamer," S3E22)

Helen Hunt

... as Jamie Buchman — a crossover of her character on the sitcom Mad About You — who mistakes Phoebe for her twin sister, Ursula. (Fun fact: Lisa Kudrow also appeared on Mad About You as Ursula.)

("The One with Two Parts: Part 1," S1E16)

Reese Witherspoon

... as Jill Green, Rachel's sister.

(2 episodes, S6E13-14)

Christina Applegate

... as Amy Green, Rachel's other sister.

(2 episodes, S9E8, S10E5)

Winona Ryder

... as Melissa Warbutron, Rachel's former sorority sister (and make-out partner).

("The One with Rachel's Big Kiss," S7E20)

Hank Azaria

... as David "the science guy," Phoebe's first major beau, who absconds to Minsk and returns years later to find her with another m

(5 episodes, S1E10, S7E11, S9E6, S9E22–23)

Paul Rudd

... as Mike, Phoebe's blind date and, ultimately, her husband.

(18 episodes, S9-10)

Anna Faris

... as Erica, mother of Chandler and Monica's adopted twins.

(5 episodes, S10E9, S10E13, S10E16, S10E19–20)

Brad Pitt

... as Will Colbert, former president of the I Hate Rachel Club (AKA, the very height of comedy, as he was married to Jennifer Aniston at the time).

("The One with the Rumor," S8E9)

Jon Lovitz

... as Steve, a restauranteur who gets stoned before sampling Monica's cooking — then, 8 seasons later, goes on a blind date with Rachel.

(2 episodes, S1E15 and S9E14)

Robin Williams & Billy Crystal

... as "Tim" and "Tomas," Central Perk customers.

("The One with the Ultimate Fighting Champion," S3E24)

Julia Roberts

... as Susie Moss, AKA "Susie Underpants," Chandler's childhood friend and present-day date.

("The One After the Superbowl: Part 2," S2E13)

Gary Oldman

... as Richard Crosby, Joey's co-star in a World War II movie.

("The One with Monica and Chandler's Wedding," S7E23-24)

Brooke Shields

... as Erika Ford, a crazy fan of Joey's Days of Our Lives character, "Dr. Drake Ramoray."

("The One After the Superbowl: Part 1," S2E12)

Bruce Willis

... as Paul Stevents, the father of the student Ross dates.

(3 episodes, S6E21-23)

Jane Lynch

... as Ellen, a real estate agent showing the house next door to Monica and Chandler's.

("The One Where Estelle Dies," S10E15)

George Clooney & Noah Wyle

... as ER doctors (har, har) Dr. Mitchell and Dr. Rosen.

("The One with Two Parts," S1E16-17)

Jason Alexander

... as Earl, a suicidal office manager whom Phoebe tries to help.

("The One Where Rosita Dies," S7E13)

Alec Baldwin

... as Parker, Phoebe's overly enthusiastic boyfriend.

(2 episodes, S8E17-18)

Dakota Fanning

... as Mackenzie, the girl whose family is moving out of Monica and Chandler's new house.

("The One with Princess Consuela," S10E14)

Freddie Prinze Jr.

... as Sandy, a nanny Ross and Rachel consider hiring for their daughter.

("The One with the Male Nanny," S9E6)

Selma Blair

... as Wendy, Chandler's flirty co-worker.

("The One with Christmas in Tulsa," S9E10)

Craig Robinson

... as the clerk who Phoebe visits as she tries to have her name changed to "Princess Consuela Bananahammock."

("The One with Princess Consuela," S10E14)

Jeff Goldblum

... as Leonard Hayes, director of a play Joey's in.

("The One with the Mugging," S9E15)

Greg Kinnear

... as Dr. Benjamin Hobart, head of Ross's grant committee — who used to date his girlfriend, Charlie.

("The One with Ross's Grant," S10E6)

Cole Sprouse

... as Ben Geller, Ross's son.

(7 episodes, S7-8)

Dermot Mulroney

... as Gavin Mitchell, Rachel's professional rival at Ralph Lauren.

(3 episodes, S9E11-13)

Aisha Tyler

... as Charlie, Joey's girlfriend — who quickly becomes Ross's girlfriend.

(9 episodes, S9E20-24, S10E1-2, S10E5-6)

Sarah "Fergie" Ferguson, Duchess of York

... as herself, sharing a photo-op with Joey.

("The One with Ross's Wedding: Part 1," S4E23)

MAE WHITMAN

... as Sarah Tuttle, the Girl Scout — I mean, "Brown Bird" — whose leg Ross breaks, and whose cookie route he subsequently takes up.

("The One Where Rachel Quits," S3E10)

Elle Macpherson

... as Janine Lacroix, Joey's roommate-turned-girlfriend.

(5 episodes, S6E7-11)

Iqbal Theba

... as a doctor who helps Joey pass his kidney stones.

("The One Hundredth," S5E3)

Jim Rash

... as "Nervous Male Passenger," who overhears Rachel's phone conversation about the plane's "broken left phalange."

("The Last One," S10E19-20)

Jean-Claude Van Damme

... as himself, filming a movie in New York — costarring with Ross's soon-to-be monkey, Marcel.

("The One After the Superbowl: Part 2," S2E13)

Tom Selleck

... as Dr. Richard Burke, Monica's May-December romance.

(9 episodes, S2E15-16, S218, S2E20, S2E23-24, S3E13, S6E24-25)

David Arquette

... as Malcom, Phoebe's twin sister's stalker (and, off-screen, Courtney Cox's husband).

("The One with the Jam," S3E3)

Olivia Williams

... as Felicity, Ross's fiancée's bridesmaid, who hooks up with Joey.

(2 episodes, S4E24, S5E1)

John Stamos

... as Zack, a colleague of Chandler's who Chandler and Monica consider as a possible sperm donor.

("The One with the Donor," S9E22)

Ellen Pompeo

... as Missy Goldberg, Ross and Chandler's former college classmate (and mutual crush).

("The One Where the Stripper Cries," S10E11)

Adam Goldberg

... as Eddie Menuek, Chandler's crazy roommate.

(3 episodes, S2E17-19)

Jennifer Grey

... as Mindy, Rachel's ex-fiancé's new beau (who, in later episodes, was replaced by a different actress).

("The One with the Evil Orthodontist," S1E20)

CHRISSIE HYNDE

... as Phoebe's ex-songwriting partner, Stephanie.

("The One with the Baby on the Bus," S2E6)

Isabella Rossellini

... as herself — and an entry on Ross's list of celebrities he's allowed to cheat with.

("The One with Frank Jr.," S3E5)

ALEX BORSTEIN

... as "Bitter Woman on Stage," the star of a one-woman show Chandler attends.

("The One with the Soap Opera Party," S9E20)

Kristin Davis

... as Erin, a one-off date of Joey's.

("The One with Ross's Library Book," S7E7)

Denise Richards

... as Cassie Geller, Ross and Monica's cousin, whom both Chandler and Phoebe fancy.

("The One with Ross and Monica's Cousin," S7E19)

Jennifer Coolidge

... as Amanda Buffamonteezi, Monica and Phoebe's old neighbor.

("The One with Ross's Tan," S10E3)

Bob Balaban

... as Frank Buffay Sr., Phoebe's dad.

("The One with Joey's Bag," S5E13)

Michael McKean

... as Leon Rastatter, creator of "Mockolate."

("The One with the List," S2E8)

Harry Shearer

... as Dr. Baldharar, a man who wants to buy Ross's monkey for his animal fighting ring.

("The One with the Fake Monica," S1E21)

FRED WILLARD

... as Dean Lipson, administrator of the San Diego Zoo, where Ross's monkey ends up.

("The One After the Superbowl: Part 1," S2E12)

Rebecca Romijn

... as Cheryl, Ross's date who turns out to be a slob.

("The One with the Dirty Girl," S4E6)

Gabrielle Union

... as Kristen, a woman who dates both Ross and Joey.

("The One with the Cheap Wedding Dress," S7E17)

Chris Parnell

... as Bob, Chandler's co-worker who can't remember his name.

("The One with Rachel's Date," S8E5)

SCOTT ADSIT

... as the director of a movie in which Joey has a full frontal nude scene.

("The One with Ross and Monica's Cousin," S7E19)

DOUG BENSON

... as Tom, friend of Rachel's date Danny. (Pictured above on Getting Doug With High .)

("The One Where Ross Moves In," S5E7)

Soleil Moon Frye

... as Katie, Joey's overly arm-punchy girlfriend.

("The One with the Girl Who Hits Joey," S5E15)

Marlo Thomas

... as Sandra Green, Rachel's mom.

(3 episodes, S2E11, S2E22, S8E20)

David "Rory's dad on Gilmore Girls" Sutcliffe

... as Kyle, AKA "Hums While He Pees," a friend of Ross and Chandler's who dates Phoebe.

("The One with the Engagement Picture," S7E5)

Arden Myrin

... as Brenda, a maid Monica suspects of stealing.

("The One with the Stain," S8E7)

Alison Sweeney

... as Jessica Ashley, Joey's Days of Our Lives co-star — an in-joke for soap fans, as she also played Sami Brady on the real Days of Our Lives.

(2 episodes, S7E18-19)

Donny Osmond

...as himself, when Joey appears on Pyramid.

("The One Where the Stripper Cries," S10E11)

LEAH REMINI

... as Lydia, a woman who gives birth with Joey's help.

("The One with the Birth," S1E23)

Matthew Ashford

... as himself —AKA, a real-life Days of Our Lives star — and Joey's guest at a cast party.

("The One with the Soap Opera Party," S9E20)

Mindy "Frau Farbissina" Sterling

... as Rachel's ex-fiancé's new wedding planner. (Pictured above as Frau Farbissina in Austin Powers.)

("The One with Barry and Mindy's Wedding," S2E24)

... and of course, JILL GOODACRE.

... as herself. Now, say it with me, kids: "Rm trrpt rnn n ERRTRRERM vrrstrbrl wth JLL GDRRCRR!"

("The One with the Blackout," S1E7)

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