Books are among the oldest forms of entertainment in the world. With these, readers can find themselves in worlds that wouldn't have been fathomed otherwise, following the adventures of the main characters all the while. As you may imagine, some books have been more successful than others, especially in terms of sales. For a better understanding of the individual books, not including series, that made the most money, here is some insight provided by Robert Jain.

The Little Prince - While this may be the lesser known book on this list, The Little Prince is nothing short of legendary in its own right. For those that don't know, this French novel details the adventures of a stranded pilot and a "little prince" that he befriends. It's not like this work was only popular in France, as it has seen numerous translations throughout the world. The Little Prince moved approximately 140 million copies, too, which makes it a financial success in the eyes of names like Bob Jain.

The Lord of the Rings - Not only was The Lord of the Rings, released in the mid-1950s, one of the most successful adventure books, but it became a worldwide hit spawning video games, movies, and even animation. As far as the original novel by J.R.R. Tolkien is concerned, its legendary status is undeniable. Not only did this novel grab people due to its setting, story, and characters, but it ended up selling approximately 150 million copies in the process. For fans of adventure, this book is recommended reading.

A Tale of Two Cities - If you're familiar with Charles Dickens' works, chances are that you've either read or heard of this novel. A Tale of Two Cities is one of the most popular fictional books with a rich history to back it up. It's far more than just the book that brought life to the quote, "it was the best of times, it was the worst of times." This is emphasized further by the fact that, since its release in 1859, it sold approximately 200 million copies.

Don Quixote - As far as best-selling individual works are concerned, Don Quixote is the name to be aware of. This Spanish novel, which incorporated elements like adventure and humor, has become one of the most legendary works in history. It is still being read in schools and universities. Furthermore, it has moved approximately 500 million units, which means that it more than earns its place in literary history.