If you're into Sci-Fi, I heartily recommend The Stars My Destination by Alfred Bester. It's an intense novel about a man consumed by his desire to exact revenge. I warn that there is a rape scene.

The Ones Who Walk Away From Omelas by Ursula K. Guin is a great short story that touches upon the topic of Utilitarianism. Not a light read.

For a lighter read, I recommend Howl's Moving Castle. A lot of people don't know about the book because of the success that the movie had, however, both are amazing in my opinion. And the book tells a completely different story from the movie so its worth picking up.

(Wait haha, I didn't realize that you didn't want non-fictions) Non-Fiction I would recommend "Hero of the Empire" by Candice Miller about Winston Churchill's escapades in South Africa during the 2nd Boer War. A fun read.