In the other thread, I recommended Game of Thrones (part of Song of Ice and Fire series). I still recommend it.
However, since you are in the mood for "philosophical"... here is one you've probably never heard of. The "Master and Margarita" by Bulgakov. It's one of the greatest novels of the 20th century, but it's very poorly known in the States. Fun facts about its creation:
- After the author wrote the first draft, he burnt it, after seeing no chance to publish something like that in USSR (this is Soviet Union circa 1928, Stalin just coming into power).
- Several years later he re-wrote it. In the novel, a similar story happens to the Master, whom the devil hands back the manuscript, and says: "Didn't you know? Manuscripts don't burn."
- The book was first published more than 25 years after the author's death.
- It has a giant black cat in it named "Behemoth".
- The apartment in Moscow, where the author lived (and where parts of the book occur) has occurred in the book, has become a gathering point for russian satanists.
Note, that you by no means have to believe in God etc to read it, but it is probably one of the most powerful pieces of literature that deals with religion, sin etc. so directly.