Here are some of my favorites which (I think) have not yet been yet posted:
The Resurrection of the Son of God by N.T. Wright
The Trinity by Augustine
On the Spirit and the Letter by Augustine
The Hammer of God by Bo Giertz
Crime and Punishment by Dostoevsky
The Cruelty of Heresy by C. FitzSimons Allison
The Reason for God by Tim Keller
Propaganda by Jacques Ellul