[brudgers]

Blood Meridian, Cormac McCarthy.

Philosphical Investigations, Ludwig Witgenstein.

The Analects.

Structure and Interpretation of Computer Programs, Ableson and Sussman.

The Hamet and The Town and The Mansion, William Faulkner.

[youngbenny]

Wittgenstein is tough reading. Amazing that he conceived of Tractatus Logico-Philosophicus in the trenches of WW1 (literally).

[brudgers]

He wrote a significant portion while a POW.

[IanChiles]

I'd also add Faulkner's The Sound and the Fury - it's excellent, despite being a bit tough to understand