I've come across a couple of Post Apocalyptic graphic novels, even though I haven't bought them, they look very cool.
The first one I came across via: http://www.warrenellis.com/?p=7519
Here's a blurb about it:
More info on the wasteland series here
“Wasteland,” the scorched-earth Oni Press series written by Antony Johnston and illustrated by Christopher Mitten, hits the 25-issue milestone in July, an impressive feat for a black and white indie comic book in a marketplace every bit as unforgiving as the barren landscape protagonists Michael and Abi must transverse within its pages.
It can be bought at OniPress: http://www.onipress.com/
Here are some more previews of 'The Wasteland' http://www.comicbookresources.com/?page=article&id=21569
Therefore Repent, is a post apocalyptic and post rapture graphic novel. It looks quite interesting as well and can be bought here: http://nomediakings.org/store
Here's a brief blurb:
What if the religious right… are actually right?Without warning, multitudes of Christians float bodily up into the sky.For the immoral majority, life goes on pretty much as usual.Except that after the Rapture, magic works — for those willing to risk demonic mutations.And an angelic army appears to have been deployed to mop up the sinners.But through it all, outsiders Raven and Mummy face the possibility of a bigger problem than the end of the world: the end of their relationship.