For me it would have to be Revolt Against the Modern World by Julius Evola. No matter where you are in life, no matter how sure you are of your beliefs, this book will at least cause you some mental conflict. I'm sure by now many of you will have either heard of it, or read it, but it's essentially the anti modernist manifesto. Evola makes great arguments for hierarchy, against secularism, against female liberation, and essentially a return to older more Pagan values. The book is very critical of Christianity, but Evola argues his points persuasively, with many of his arguments being hard to deny. The book certainly hasn't made me a Pagan, but it's certainly made me think, so I'd highly recommend it.
What book would you choose?
I'm sorry to be that person but the book is called Nineteen Eighty-Four.
The film is called 1984.
Feel like such a twat doing that but I feel for some reason that I can't put my finger on that it matters.
Yes I would recommend that, definitely, I'm not really a reader and that one I've read at least ten times, not recently though for some reason.
This is the only acceptable answer.