I can't belive no one mentioned Fist of the north star.
Perhaps it's closer to the Fallout 2 setting when i come to think of it.
If you can bear watch it that is: http://www.youtube.com/watch?v=xX9AGkd290Q&feature=related
Yeah, the Kenshiro type of character is one I've heard a lot of people playing in Fallout. That is, give someone a high Agilitiy, Luck and Strength raise their critical rate as high as possible (maybe with the Finesse perk) and give them Bloody Mess. Go around punching people, getting endless crits and blowing body parts off.
Anyway, has anyone mentioned [url=http://en.wikipedia.org/wiki/Brazil_(film)]Brazil[/url], the Terry Gilliam film? I think that's been stated as an inspiration. I've seen it, and it's certainly very good, although it reminded me more of what Brave New World and 1984 would be like if done by the Monty Python crew than anything else. That said, I was drinking at the time and by the end I had no idea what was going on, so maybe the links are there at the end. Maybe it was just the satirical element that was the inspiration.
There's a fairly old British cartoon about nuclear war called [url=http://en.wikipedia.org/wiki/When_the_Wind_Blows_(film)]When The Wind Blows[/url]. It's one of those things that's technically a family programme - it's just an old couple trying to make their house "nuclear bomb proof" - but it's so massively grim and harrowing that it's the kind of thing that would give kids nightmares. The guy that mentioned Threads reminded me of this.
Incidentally, there are lots of film reference throughout the games. While not overtly similar to the games themselves (i.e. post-apocalyptic) they do often feature similar outlooks, or the setting of a lone wanderer moving through an inhospitable environment or other elements. One such film that's referred to is The Good, The Bad and The Ugly - in Fallout 2 you find dog-tags with the three main characters' names on. So it's not necessarily related in an obvious sense but these references films and books in the series still obviously inspired the people that made the games (ah, just remembered the Hitchhiker's Guide reference in that random encounter).