I read the following 3 in this order and it definitely co-incided with a change in my life for the better:
* A confession and other religious stories by Leo Tolstoy
* Happiness by Matthieu Ricard (a counter argument against French philosophers who believe happiness doesn't exist)
* The Diary of Anne Frank
* A Life Interrupted by Etty Hillesum (the most beautiful book I will ever read)
"The Kingdom of God Is Within You" by Tolstoy is definitely a top book for me. I find that I understand it in a slightly different way each time I read it.
* A confession and other religious stories by Leo Tolstoy * Happiness by Matthieu Ricard (a counter argument against French philosophers who believe happiness doesn't exist) * The Diary of Anne Frank * A Life Interrupted by Etty Hillesum (the most beautiful book I will ever read)