Perennial Seller is pretty good, and sets up a really nice mindset for product/business creation, but by far my favourite book of Ryan's is Trust Me I'm Lying... that book changed the way I looked at the Internet, and how the things we see in our social feeds come to be in our social feeds.
It definitely broke my mind for a little while
Obstacle Is The Way for me....But all his stuff is great. I enjoyed Trust Me a ton as well!
Hah, I think Trust Me just feeds that monster inside me that craves world domination, which is probably why I enjoyed it.