Led Zeppelin IV by Led Zeppelin 1971

A bit like the latter day Prince, this album controversially had no name. It's therefore been referred to by many different names ever since - mostly by the moniker of "Led Zeppelin IV", although it has also often been referred to using four symbols, as "Untitled", "The Runes", "The Hermit" and so on. The lack of a name certainly hasn't had an adverse affect on sales. 37 million copies have flown off the shelves to date...