I don’t know that I would be willing to identify a “best” book, and while I’ve read the Bible in its entirety multiple times in a number of different translations (New American, New Jerusalem, Today’s English, King James, Douai-Rheims, Knox, much of the Anchor Bible, and currently working through the Vulgate), I don’t know that I would necessarily put any of those in the best book category (although I think it’s kind of essential cultural background reading regardless of one’s beliefs). It’s kind of hard to decide, for example, the relative rankings of say Chekhov vs. Calvin and Hobbes and I don’t think I want to try. I have included my favorite reads of each year for the past few years at https://www.dahosek.com/category/reading/ (although that also includes other blog posts about reading).