Sitcom premises don't get much more straightforward then Friends. It's about a group of friends in their twenties who live in New York and interact with each other the way that friends do, highs and lows and all. Also all the episodes are "the one where x does y". And yet what came from those simple beginnings spawned a decade long pop culture phenomenon that did everything from inventing hairstyles to putting previously unknown actors and actresses like Jennifer Garner on the map. Although its spin-off series about Joey may not have experienced similar levels of success, Friends left quite a mark on television history. These shirts will certainly be there for you when the rain starts to pour.