Illustration: Jared Fanning
I had an inclination that The Bible would be number one, but I had no idea by how much. I think it is a little skewed because of the chosen statistics. For one, it is over the last 50 years - which is a long span of time. The first Harry Potter book wasn't published until 1997. The Da Vinci Code was published in 2003. I will not bother to look up Twilight. Ew, Twilight. Also this is based on books sold, I am sure The Bible does a whole lot of selling to churches and what not.
I would love to see this with just the last 10-12 years. I am not sure what other metric could be used besides sales but it would be worth looking into.
-Via Bits and Pieces
If you think that LOTR established the pattern for long stories over multiple volumes, you may not have heard of Homer, who pre-dates Tolkien (and much of the Bible) by a significant margin.