I’m a Jesus Follower so that makes The Bible the most important book and therefore the one I most recommend. I really like the single column format for ease of reading as opposed to the traditional 2 column that most people use. The single column is more comfortable and for me feels more personal. If you haven’t tried it, you should, I think you’ll like it.
And for those that might be reading this that aren’t Jesus Followers, I’m sure you know that there are many great thoughts and ideas that have found their way into everyday life, that people reference. You can use it as a source for when people do mention a passage. Don’t let any past issues or prejudices keep you away from wisdom, so matter where it comes from.