Others have mentioned it, but I just read The Road by Cormac McCarthy.
I think the book is probably less... something than the film. I turned the film off after maybe 10 minutes a couple of years ago.
Some say the book is horror, rather than sci fi. I kept waiting for something really bad to happen... but the whole book is really bad. I mean, the setting is bad, the stuff that happens is mostly a grind with a few very disturbing events along the way.
A very fast read. ~300 pages I think but fairly large font.
Not sure quite what to make of it but it's very good. Horror, yes (I don't like horror). Moving. Depressing, sort've. Stark, bleak, beautiful (sort've).
Worth a read.