My all-time favorite episode of "Friends," and I think this is the case for many, is “The One With The Embryos” from Season 4. While it’s named after the storyline regarding Phoebe and her pregnancy, the part of the episode that sticks with me is the silly trivia contest that led to Chandler and Joey switching apartments with Monica and Rachel after they made a bet. It’s a hilarious game of whits that leads to one of the most jarring and hysterical plot points when the boys join the list of people to live in Monica’s apartment and the story behind how this episode came to make it even better.