I know everyone is going to say The Road, BUT I think it is realistic but only if the scenario is as bad as depicted(all wildlife gone, no crops harvested in a decade) otherwise I doubt desperation would get that desperate.
I’m leaning towards voting for Jeremiah which was an obscure little show where the scenario was that a virus killed everyone past puberty, I thought it had a fairly good depiction of what would follow if a little too cheerful. (don’t bother pointing out the stupid shit I know).
I think my problem with a lot of depictions is that either they are ridiculously bleak, or ridiculously cheerful, there is no middle ground. So while the roads might be rob and rape fests there is no way people aren’t going to gather into protected communities, and cannibalism is not turned to in the first 6 hours.
Even before Threads, there was Peter Watkins’ The War Game*, still, to my mind, the best and scariest depiction of Nuclear War. It was commisioned by the BBC back in 1965, but wasn’t shown by them until twenty years later
Threads is a worthy successor, updated and in color. But one of the things that makes The War Game so convincing is its black and white medium, and its hand-held “Arriflex” shakiness. You see shell-shocked people in the aftermath, vacant-eyed and rocking, and you’re not sure if the dark blotches on them are blood or dirt.
Other films don’t come close. The Day After was scary enough, with State of the Art effects, but it seemed too “clean” and neat.
*Not to be confused with the 1983 Matthew Broderick/John Wood film War Games
Testament seems to be a fairly realistic treatment of the aftermath of nuclear war — when you’re living far enough away from the bombs that they don’t kill you immediately, but nuclear fallout and crumbling civilization instead kill you gradually.
Not a movie, a book. Soft Apocalypse by Will McIntosh. No major event, just a slow decline, followed by people who try fix it be revolutionary means, only to screw it up more. Very good book.
I once watched an animated short that was about the aftermath of a nuclear attack in England. It was the story of an old couple. Its not much of a post apocalyptic depiction (its actually the apocalypsis).
That short is the most disturbing thing I have ever watched and I know that the good folks at the SDMB will tell me its name
It’s not exactly a post-Apocalyptic book, since there is no one apocalyptic event, but the book Soft Apocalypse presents an interesting take on what happens when a combination of economic collapse, disease, crime, war, and various other events and factors combine to cause society to slowly come unwound.
Alas, Babylon* follows the residents of a central Florida town for about a year following WWIII (which lasts approximately a day). It’s very much a product of its time — 1959 — and contains both attitudes and technology that seem positively quaint; but taken in that context, it’s a good depiction of people trying to hold on to as much of civilization as they can.
*Known in some circles as “Alas, Babble-on” due to the author’s (perceived) style.
Try the novel Earth Abides. It’s over 60 years old and somewhat quaint in parts because of that, but it’s the most likely example of “what if?” that I’ve come across.
The slowly creeping cloud of radiation wasn’t really a feature of nuclear weapons at the time of the book or after (why would anyone build a weapon whose effects would so easily cross back into the attacking country). It was a pretty cool idea for a story, as it had a lot of dramatic possibilities and was a good metaphor for nuclear proliferation, but I don’t think I’d call it “realistic”.