Re: post-apocalyptic fiction?
I also loved The Road by Cormac McCarthy. It has popped up a few times already in this thread. Fantastic novel, though very depressing, not everyones cup of tea.
More on the futuristic Sci-Fi side of things, I loved Battlefield Earth by L. Ron Hubbard. Hubbard cops a lot of flak, justifiably so, due to scientology but don't worry, no thetins in this book, it is a brilliant novel, an amazing work of fiction.
Also, while we are discussing fiction and not necissarily books, I need to recommend the video game series Fallout. Some very quirky, funny moments, some much darker ones and overall an immersive experience and a true testament to humanities ability to persevere, adapt and never learn from it's mistakes.
A disquiet mind at therapy with the music.