There are hundreds of amazing things to love about Friends. Not only was the show on for 10 seasons, but it remained excellent all the way through. As we know, most shows that surpass 7 seasons usually don't finish as strong as they started (*cough *cough How I Met Your Mother). While Friends certainly hit some rough patches, the hilarious writing and the never-ending chemistry shared between all 6 of the leading cast members, ensured the show never strayed too far from its roots.

Apart from a lovable cast and a team of skilled writers, Friends also had one major thing that other shows from its time didn't. We are talking STAR POWER! Every celebrity back then wanted in on the action. We saw some huge Hollywood names cameo in the series over the years and we are still gushing over it today. Here is a ranking of the 20 best (and worst) celebrity cameos featured in Friends.

20 Gabrielle Union Caught Joey And Ross's Eye In Season 7

Gabrielle Union played the role of Kristen Lang in an episode of the 7th season. Both Joey and Ross ran into her while she was moving into a nearby apartment. Both guys were immediately interested, though their battle over her got so intense, that she wound up running from both.

19 Leah Remini Originally Auditioned For The Role Of Monica

Even though the role of Monica Geller definitely went to the right actress, had Courtney Cox not been an option, we can actually see Leah Remini making it work (though the character would have been a lot surlier). After not landing the role she initially auditioned for, Leah Remini returned as Lydia. She was a pregnant woman at the hospital during the episode where Carol gave birth to Ben.

18 Alec Baldwin Annoyed More Than Just Phoebe...

For 2 episodes of the 8th season, Phoebe Buffay was dating Parker. Parker, as many will remember, was played by the famous Alec Baldwin. The relationship didn't work out due to the fact that Parker was overly optimistic and giddy about, well, everything. After 2 episodes, we were just as done as Pheebs.

17 Anna Faris Is The Mother Of Chandler & Monica's Twins

Here is one we are sure everyone will easily remember. In the final season, Monica and Chandler decided to adopt a baby. Anna Faris' character Erica, was the pregnant woman who selected them to be the future parents of her babies. Of course, she wasn't the brightest, so she didn't realize she was having twins until she was literally having twins, but the Bings wound up as happy parents nonetheless!

16 Robin Williams & Billy Crystal's Cameo Was A Complete Fluke

Robin Williams and Billy Crystal were at one point everyone's favorite besties in Hollywood. While the 2 legends probably deserve a higher ranking on this list, since they were never supposed to be on the show in the first place, they've landed here. While filming on a nearby set, the two accidently walked in while Friends was shooting. Writers quickly jumped at their chance and asked if they wanted to participate.

15 Sean Penn's Storyline Got Real Creepy, Real Fast

Had Phoebe met Sean Penn's character Eric under literally any other circumstances, we probably would have shipped them. However, the fact that they only met because he was engaged to her twin sister, wasn't a great way to sell us on the pair. Without getting into the creepy details, we'll end simply with saying that they didn't work out as a couple...

14 Joey Was Mesmerized By Susan Sarandon's Character

During the 7th season, the famous Susan Sarandon stepped in to play Joey's Days of Our Lives co-star, Cecilia Monroe. She was totally extra and over-the-top, but we were living for every minute of it! When the soap opera killed off Monroe's character, her brain was given to Joey's Dr. Drake Ramoray.

13 Charlie Sheen Really Pulled Off Those Chickenpox

In season 2, we learned that Phoebe had an ongoing relationship with a military man who would spend months at a time in a submarine. In the episode, her sailor surfaced and he turned out to be none other than Charlie Sheen. Unfortunately, their reunion hit a snag when they both came down with a bad case of chickenpox.

12 Ben Stiller's Character Went Too Far When He Yelled At The Chick And The Duck

In season 3, Rachel had a brief fling with a man named Tommy, who was played by Ben Stiller. Tommy had a bad temper, but only poor Ross knew about this at first and nobody believed him. However, when the gang caught Tommy yelling at their beloved chick and duck, he was rightfully sent packing. "STEP AWAY FROM THE DUCK".

11 Brooke Shields' Soap Opera Obsessed Character Was Everything

Famous model Brooke Shields got lucky with her hilarious storyline. In the 2nd season, she played Erica, a delusional fan obsessed with Joey's character on Days of Our Lives. Erica believed that Joey was actually Dr. Drake Ramoray and truly thought the soap opera and all of its drama was real.

10 Ray Ray Green & Melissa Warburton Forever

In the 7th season, we got to see the talented Winona Ryder make a hilarious appearance on Friends. She played Melissa Warburton, an old college friend of Rachel's. While Rachel reminisced about a wild night they once shared, Phoebe chimed in to say that she didn't buy the tale. A frustrated Rachel then looked to Melissa to confirm the story, but got a bit more than she was hoping for...

9 Dakota Fanning Was Just The Friend Joey Needed

When Monica and Chandler announced they'd be moving out of the city, Joey was naturally the one who had the hardest time dealing with the major news. While visiting the Bing's new home, Joey met Mackenzie, a little girl and current resident of the home his friends were purchasing. The best part about this cameo? When Chandler convinced Joey that Mackenzie was a ghost.

8 Hugh Laurie Got To Say What We Were All Thinking

Don't get us wrong, we love both Ross and Rachel, but watching them screw things up time and time again was not easy to do! So, when Hugh Laurie appeared in the season 4 finale episode as a disgruntled man sitting next to a whining Rachel on a flight, we were so happy to hear him tell her the truth!

7 Christina Applegate Is A Green Girl!

Christina Applegate was the second famous sister Rachel Green got on the show, but more on the other one later. Applegate portrayed the character Amy Green and did a smash-up job. Her character was annoying for sure, but in a way that made us wish she had shown up in more than just 2 episodes.

6 George Clooney And Noah Wyle Gave Us The Ultimate 90s Crossover

For those who never watched ER, you might not have even known that this celebrity cameo was actually a crossover. Back in the 90s, Friends and ER were two of the biggest shows on television, so naturally fans freaked when this happened. When Rachel injures her foot and goes to the hospital with Monica, the girls score a date with Dr. Doug Ross and Dr. John Cater (Clooney and Wyle's ER characters).

5 We Are Still Giggling Over Danny DeVito's Cameo

Who could ever forget about Officer Goodbody, right? In the 10th season, Phoebe is finally an engaged woman and looking forward to her bachelorette party. However, when Monica and Rachel plan her an elegant event, instead of the raunchy one of her dreams, they decided to call upon a last-minute stripper. Que Danny DeVito!

4 Reese Witherspoon And Jennifer Aniston Are Besties In Real Life, But Sisters On Friends!

Is it just us, or is the Green family gene pool mighty impressive? Christina Applegate, Jennifer Aniston AND Reese Witherspoon? What a trio! We met Witherspoon's character back in season 6 and most of us were fans right off the bat. Since she and Aniston have always been besties IRL, their chemistry was spot on.

3 Julia Roberts IS Susie Underpants!

One of the all time best cameos in Friends history, has to be the one by Julia Roberts. Let's all keep in mind that back in the 90s, Julia Roberts was THE actress (which just made her storyline even funnier). Robert's played Susie "Underpants" Moss, a childhood acquaintance of Chandler's who was holding quite a grudge against him for coining her embarrassing nickname.

2 Nobody Hated Rachel More Than Brad Pitt's Character

At the time of his cameo, Pitt was still married to Aniston. This being the case, the fact that writers wrote Pitt's character to be a kid from Rachel's high school who loathed her, was a stroke of genius. Will Colbert had gone to school with Rachel and the Gellers. It was even revealed that he and Ross were founding members of the "I Hate Rachel Club".

1 Bruce Willis' Cameo Landed Him An Emmy Award

Bruce Willis really is a neat guy! Back in season 6, Willis appeared as the father of Ross' extremely young girlfriend. Obviously, he wasn't happy with Ross, but he did have a fling with our girl, Rachel. The scene where Ross catches him talking himself up in front of a mirror, is pure comedy gold. Willis took home the Emmy for Best Guest Actor in a comedy.