When Monica and Rachel challenge Joey and Chandler to a game of trivia about each other, Monica's crazy competitive streak leads to the winner securing the girls' apartment. When the girls ultimately lose, the pairs actually go along with the deal. Not only is this probably illegal in so many ways, but I highly doubt the high-strung and control freak that is Monica would actually allow this to happen. However, the trade did make for a great few episodes and a grand entrance that is still iconic to this day.