Paul Ryan talks about which books he re-reads most often:
"The Bible, Friedrich von Hayek's The Road to Serfdom and Ayn Rand's Atlas Shrugged."
- Insight on the News
These three books are, presumably, the books which have had the most influence on Paul Ryan's thinking regarding morality, politics, economics, and more. It's noteworthy that the second two are very similar to each other in terms of their political and economic ideology but have little in common with the first.