From George Clooney to Julia Roberts: The Best Guest Stars on Friends

It may be all about the core six, but the gang had many famous faces join them along the way

BRAD PITT

Jennifer Aniston's then-husband guest-starred on the season 8 Thanksgiving episode "The One with the Rumor" as a former high school classmate of Ross, Monica and Rachel's – who had a pure, unadulterated hatred of Rachel.