Season 3: Having really hit its comedic stride, the third season did the smart thing and showed a more serious side to the Friends ' frivolous nature. There was fun introducing the chick and the duck, poking ""Ugly Naked Guy" with a stick and "T.O.W. The Princess Leia Fantasy" (for which George Lucas sent a "thank you" note). Then after establishing a few cracks in their otherwise fairy-tale union, "T.O.W. Ross and Rachel Take a Break" offered admirable contrast. From here on in, the awkward catchphrase "we were on a break" became a hard-hitting reminder that love hurts. The other s' relationships were naturally no less complicated. "T.O.W. Monica and Richard are Just Friends" teased a now moustache-free Tom Selleck into thinking he might be "the one". Then Pete (Jon Favreau) tried his hand before insanely wanting to become "The Ultimate Fighting Champion". This episode pulled off an incredible double guest surprise from Billy Crystal and Robin Williams, proving just how popular the show had become. To that list were added cameos from Ben Stiller as "The Screamer", Sherilyn Fenn as one of Joey's exs and Isabella Rossellini, who taught Ross to never fantasise on laminated plastic. The cast were fitting in film roles where possible. Cox appeared in Scream , then brought David Arquette back with her for a cameo, which kept their off-screen chemistry alive. The final surprise was Teri Garr as Phoebe, Sr in "T.O. At the Beach", where it was hinted that something might be salvaged between Ross and Rachel after all. -- Paul Tonks