10 of the Biggest ‘Friends’ Cameos

It’s been 20 years since “Friends” debuted on NBC. The hit sitcom premiered on Sept. 22, 1994, and  made headlines throughout its decade-long run with endless Emmy nods and history-making paydays for the show’s six stars, and it boasted an impressive lineup of guest stars in the process.

Check out 10 of the most memorable “Friends” guest stars.

George Clooney and Noah Wyle

TV docs George Clooney and Noah Wyle crossed over in a Season 1 “Friends” episode, when Rachel (Jennifer Aniston) switched identities with Monica (Courteney Cox) so she could use her medical insurance. The episode was “The One With Two Parts, Part 2,” when Rachel spoke for us all when she asked this burning question to “ER” hunk Wyle: “Aren’t you a little cute to be a doctor?”

Charlie Sheen

Season 2 brought Charlie Sheen to the “Friends” set in the episode “The One With the Chicken Pox.” He played Phoebe’s (Lisa Kudrow) old boyfriend Ryan, who came to visit while on a two week leave from the Navy. Unfortunately, Pheebs had a case of the chicken pox, so the visit included more scratching than kissing.

Charlton Heston

He once parted the Red Sea, but “The Ten Commandments” icon Charlton Heston met his match when a stinky Joey Tribbiani (Matt LeBlanc) invaded his shower on the Season 4 episode “The One With Joey’s Dirty Day.” When struggling actor Joey borrowed Heston’s dressing room shower, the movie star busted him and warned, “Put some pants on kid so I can kick your butt.” When Joey tried to explain that he “stinks” (he’d just returned from a three-day fishing trip),  a confused Heston tried to comfort him with, “Every actor thinks he stinks, even Lawrence Oliver at sometimes thought he stank, Bob Redford won’t even watch himself...”

Julia Roberts, Brooke Shields, Jean-Claude Van Damme, Chris Isaak, Fred Willard, Dan Castenella

“The One After the Super Bowl” was a double-length 1996 episode with a star-studded, supersized cast.  Brooke Shields as a stalker? Check. Julia Roberts as Chandler’s grade school tormenter? Yep! The hour-long  episode aired immediately following NBC’s broadcast of the Super Bowl and was the most-watched post episode in the show’s history, and well as the top rated post-Super Bowl episode of all time.

Billy Crystal and Robin Williams

The year was 1997 and the movie was “Father’s Day.” Comedians Billy Crystal and Robin Williams did a crossover cameo on “Friends” to generate buzz for the flick.  The duo appeared on the pre-credit teaser sequence of the third season episode “The One With the Ultimate Fighting Champion,” playing Central Perk customers trying to have a private conversation amid six pairs of big ears.

Bruce Willis

Actor Bruce Willis scored an Emmy for his appearance in the Season 6 episode “The One Where Ross Meets Elizabeth’s Dad.” He played Paul Stevens, the father of Ross’s college student girlfriend and the older suitor of Rachel (Jennifer Aniston).

John Stamos

“Full House” alum John Stamos turned up on Season 9’s “The One With the Donor,” playing Zack, a work colleague Chandler (Matthew Perry) was eyeing to be a sperm donor. “Zack may be the guy!” an excited Chandler told Monica. “I mean, look, he's intelligent, he's healthy, he's athletic, I mean, he is ‘spermtastic!’ I'm telling you, he's great! I mean, even if my sperm worked fine, I'd think he'd be the way to go!” The duo drilled Zack with questions about his family medical history before complimenting his perfect set of teeth.

Reese Witherspoon

The “Legally Blonde” star guest starred on “Friends” as spoiled rich girl Jill Green in “The One With Rachel’s Sister.” In 2011, Witherspoon revealed that she had stage fright during the live taping of the sitcom. According to Us Weekly, Witherspoon said, "In all my enthusiasm, I completely forgot something crucial...I had never been on television [or] in front of a live audience ever in my entire life. And I panicked! I totally froze! I couldn't remember my lines and the writers were yelling ... I just stood there absolutely completely frozen." She credits Aniston with giving her a pep talk.

Brad Pitt

Back when he was still married to Jennifer Aniston, Brad Pitt appeared on the 2001 Thanksgiving-themed episode, “The One With the Rumor.”  He played Rachel’s high school nemesis Will, a former geek whose claim to gain was founding the “I Hate Rachel Green Club.”  He also spread a pretty nasty rumor about her having both male and female reproductive parts. Pass the yams, please.

Sean Penn

Oscar winning actor Sean Penn appeared on two 2001 “Friends” episode as Eric, the fiance of Phoebe’s identical twin sister Ursula. In “The One With the Halloween party,” viewers met Eric. In “The One With the Stain,” things got a little weird when Eric realized he had a thing for Phoebe, and even weirder when he confused Ursula for Phoebe, and…well, you get the picture.