Every weekday evening on Columbia Broadcasting's (CBS) Late Show, host David Letterman delivers his tongue-in-cheek top ten lists. The lists have become one of the most recognisable symbols of American popular culture. Part of the humour lies in the pithy ranked statements about current events. However, much of the fun resides in Letterman's mockery of our obsession with rankings – rankings of everything from automobiles to college football teams to human attractiveness. The humour is sustained from night to night, week to week, year to year because of our uneasiness with rankings as a very powerful and enduring value-organising tool.