A list of the best selling books of all time, fiction and nonfiction best sellers. What are the best selling books of all time? Since religious and political books, such as The Holy Bible, are often given away for free, they have not been included on this list. These top selling books span multiple centuries, covering many genres and original languages. And if you think Harry Potter or Twilight top this list, think again, they're not even close. What books sell the most? That said, the most popular books are indeed novels, with the most popular published volumes going through multiple editions and reprints. What are the best selling books in history? A few nonfiction texts can also be found, but they are few and far between. If one enjoys reading, these are the best sellers of all bestsellers, as well as the answer to the question "what are the best selling books of all time?"