Thanks for all the suggestions, i am reading Systemic Shock right now, but it seems more apocalyptic than post-apocalyptic, as far as i read (~70%) it is about the War, not after it.
To clarify: it does not have to be filled with action from cover to cover. But for instance in Lucifers Hammer there are approx. 100 pages (or even more?) on which the character only drivers around the US and describes what he sees. And that bores me.
As soon as i finnished with Systemic Shock im gonna try another one of those mentioned.