Now, by all means, I've been a fan of the Mad Max movies, the old Kurt Russell Escape From New York movie, A Boy and His Dog and many others relating to the "Fallout Feel," but NONE have even come close to comparing to the 2008 release, Doomsday.
I just finished watching the movie and could relate every single character, every single aspect of the movie to Fallout. There are ruins, there are raiders, there are mohawks, there are biker goggles, there are technology seekers, there are scientists, there are specialists, there are snipers, there are various uses of weapons, there are "armor-clad" warriors, there are cars, there are trains, there are cannibals, there is devastation, there is leather armor, these is technology and ultimaley, the source, the very meaning, as in every Fallout game ever released, there is a way to fix things... A cure. A way to make things... better. Plus! The most bad-ass post-apocalypic car chase scene you have ever seen your entire life...
While the movie doesn't take place after "Nuclear-Bombs" exploded, there is another reason for the end of the world and the survivors in this movie are the most realistic and BEST comparison to the Fallout series I've EVER seen. For those that are confused on what movies might relate to Fallout and want to watch a movie that is absolutely "today" and not the boring 1980s or even 1970s filmography, THIS is the movie for you. If you're a huge fan of the Fallout series, as I am and YOU haven't seen Doomsday.... Go rent/buy. It will place you directly in the seat of the vault dweller if you're one that can look past the aspect that a nuclear war didn't happen but a plague that wiped out the world instead.
Don't worry, the world still looks completely devastated and destroyed, as it should! Caution: The movie isn't for the faint-hearted and it shouldn't matter for Fallout fans anyways! This movie = Fallout 3
*Edit* Ah, as an endnote: For anybody that can give me a more accurate description of a Fallout "Raider" than this movie considering their party in Glasgow, please try.