Interestingly, there's a page for that on Wikipedia.

http://en.wikipedia.org/wiki/Category:Post-apocalyptic_comics
(Not sure how good it is.... I haven't read all that many of those comics. A bit of Judge Dredd & DMZ, neither of which are terribly Fallout-like. Although Judge Dredd has the over-the-top black humor thing going. I also don't think the anime/manga page there is very well developed.
Only other "post-apocalypse" things I've read are Transmetropolitan (which is more political/social satire, less blasted wasteland) and Battle Angel Alita (it's got wasteland, but it's also got plenty of crazy Japanese manga combat-cyborg action, strange philosophy, and gratuitous German :tongue:)