I just finished reading The Road by Cormac McCarthy and I highly recommend it. The basic idea is an old chestnut indeed. A man wanders through post-apocalyptic America. But the man has his young son with him, and it is his ferocious love for the boy that raises this tale above the level of cliche. In addition, you have McCarthy's wonderful prose, stripped down a bit here in service to the story but still beautifully wrought.
There are experimental elements in the book as well, which I suppose is why "critics" can treat this as a literary novel instead of the genre novel it clearly is. There are no chapters, just illustrative scenes, and, for reasons unknown, McCarthy doesn't use quotation marks to indicate dialogue and doesn't put apostraphes in his contractions. The contraction thing bothered me a bit at first, but I got used to it. The lack of "chapters" worked perfectly and I never had any trouble telling where the dialogue was coming from. Of course, the vast majority of the book never shows more than two people interacting.
The book is also short and a quick read. I finished it in one day. But its effects have lingered.