The Road by Cormac McCarthy
It's cliche I suppose, but 1984 by Orwell. It's actually a fucking great read beyond it's thematic meaning. People are correct in saying A Brave New World was more prescient, but it's not as good a book in my opinion.
Joe Abercrombie's The First Law series, all six mainline books and even the side books are all fantastic.
It's manga, but Berserk by Kentaro Miura. IYKYK
Same, seeing him blatantly slander the Apollo dev sealed the deal for me. My account is still active, but come June 30th, it's gone.
The quality of his answers, considering the scope of the conversation, was extremely lacking.