i second The Road. also world war Z by max brooks The handmaids tale. Its not post apocalyptic, but its a really grim future story
I have been wanting to get my hands on World War Z for some time. I will check out the Handmaid's Tale. Edit: Love the sig btw. "won't eat anything I couldn't beat in a fight". lol. That one's new by me.
If you're looking for something like The Road then this book will disappoint. But if you're looking for some a hilariously fucked up romp through a post apocalyptic America then this book will deliver. It's the type of book that doesn't make you think too hard but keeps you interested.