This album, with its title-less cover, (it is called, and obviously now accepted, as "Led Zeppelin IV, even though it offically has no title) is, in all honesty, legendary. It is, in my opinion, and most Zeppelin fan's opinion, their best. It has sold the most copies by far. 22,000,000 copies to date. (a stat from 1999) That places Led Zeppelin IV at number 7 on the all-time, best selling albums list. Every single track on this album is well known, and most people have heard of them before. It includes the famous song "Stairway to Heaven." Quite possibly the most famous rock song ever. And the best part about it, Zeppelin didn't even put out a single. And also, they were well known for being camera shy, giving very few interviews.