Buzz·Posted on May 26, 201320 Best Celebrity Guest Stars On FriendsLet the countdown begin.by Spencer AlthouseBuzzFeed StaffLinkFacebookPinterestTwitterMail 20. John Stamos 19. Jim Rash View this video on YouTube Season 10, Episode 19: The Last One: Part 1Season 10, Episode 20: The Last One: Part 2Academy Award winner Jim Rash is only credited as 'nervous male passenger' in the final two episodes of Friends, but his one-liners make the character unforgettable. In the episode, Phoebe tries to contact Rachel before her flight for Paris departs. In order to buy some time, Phoebe claims that there is a problem with the plane's left phalange. Jim Rash's character overhears the phone conversation and abandons the plane, claiming: "oh, my god! This plane doesn't even have a phalange!" 18. Ben Stiller 17. Robin Williams and Billy Crystal 16. Sean Penn 15. Brooke Shields 14. Dakota Fanning 13. Dick Clark View this video on YouTube Season 6, Episode 10: The One with the RoutineThough Dick Clark never actually appeared in this episode, his name was mentioned several times, resulting in one of the greatest "Friends" scenes ever. Ross and Monica appear as background dancers for Dick Clark's New Years Eve TV broadcast, but they want more screen time on camera, so they perform their childhood dance routine. 12. George Clooney and Noah Wyle 11. Christina Applegate 10. Alec Baldwin 9. Julia Roberts 8. Jennifer Coolidge 7. Jason Alexander 6. Winona Ryder Tap to play GIF Tap to play GIF 5. Paul Rudd 4. Tom Selleck 3. Danny DeVito Tap to play GIF Tap to play GIF 2. Bruce Willis Tap to play GIF Tap to play GIF 1. Brad Pitt Tap to play GIF Tap to play GIF