Bhagavad-gita Made My Life More Enjoyable
I've been religious since childhood, but my the Episcopal Christianity of my youth felt too burdened by fear to inspire my adult actions.
Then I encountered the Bhagavad-gita and my soul soared. Reading it not make me non-Christian, but it gave me a perspective that I felt came closer to that of Jesus and the early apostles, to whom Jesus taught a simple doctrine of the Way, which is remarkably similar to what Krishna teaches to Arjuna in the Gita.
The Gita has much specific information about the soul, and various ways to elevate one's thoughts and conciousness, culminating in pure loving devotion to the Supreme Absolute Truth, the Personality of Godhead.
The transubstantiation of flesh into spirit
These will always be a few of my favorites:
The Last Temptation of Christ by Kazantsakis
Steppenwolf and Demian, both by Hermann Hesse
The Valis trilogy, esp. The Transmigration of Timothy Archer by Phillip K. Dick
The Colossus of Maroussai and the Nexus trilogy by Henry Miller
The Stranger by Camus
Focault's Pendulum by Umberto Eco
and of course On the Road by Kerouac, which propelled me through much intercollegiate disillusionment...;) ;)