The next book on my reading lists of the 100 Greatest Books is The Colour of Magic by Terry Pratchett. You can find this book on the BBC and My Book lists.
I started reading this book because I was looking for something easy to read and I noticed that all of the Terry Pratchett books were pretty cheap for the paperbacks so I picked up all 4 on the list. I was going to start with Mort until I realized that these were books all within a series of books called the Discworld series, and The Colour of Magic was book 1. It turns out that this is a fanstasy series that takes place in a realm where the planet is a flat disk on the back of four elephants whom stand on a turtle. Other than that, something you may need to know is that magic is a major component of the story. But all in all, I really really enjoyed it. His humor is a bit off and not always what you would expect, which is what makes it enjoyable. The type of humor reminds me of Futurama in which at one point the main character asks if anyone else tastes purple. That is the sort of thing you could expect from this book. It basically follows the exploits of a failed wizard and a tourist from a distant continent. I would actually really recommend this book and likely this series, which contains about 40 books (but I haven't read any further into the series as of yet). Although now I will have to read them in order, even though the books on this list jump around a little bit. But for those who don't want to read all the books the author has stated that that is not always necessary since the individual stories should stand on their own. But I would probably recommend this book as the first one you read since it gives a pretty good introduction to the realm in which it takes place.