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


The Two and a Half Men star was in the season 2 episode "The One with the Chicken Pox," in which he played an ex-boyfriend of Phoebe's – a sailor who spends years at a time living in a submarine. When he's above ground for two weeks to spend some time with Phoebe, however, the two come down with the chicken pox – but manage to make his stay romantic regardless.