The Brothers Karamazov
Fyodor Dostoevsky
Read:
The Brothers Karamazov is a treatise on how life should (not) be lived disguised as a murder mystery. Any description of the plot would do the book a disservice: it is really not the point. It is instead all about the meandering way in which it slowly unravels, taking its time with long digressions on the consequences of rising atheism and socialism in 19th-century Russia, the existence and role of God or how to balance faith and reason in service of a happy, meaningful life.
I might come back and write something more in-depth, but anything worth writing (let alone reading) would take me much more time that I have now, as well as a reread or two.