These are ones that I haven't seen for a while and must only remember. Thus I can't give any of them a full review.
Miracle Mile: Boy meets girl but sleeps through his alarm, waking up to miss his date and take a call from a diner payphone that informs him that of an imminent nuclear attack on the city. Progresses with authentic dream logic but a real sense of urgency. You will not expect the ending. If you find a copy, do NOT allow anyone to spoil it for you.
Day of the Beast: Spanish film from the 90s poses the question what if you knew the apocalypse was coming but nobody believed you and stretches further to ask: then, if you prevented it how could you convince anyone. Mostly comedic but knows when it has to be a horror movie.
Letters From a Dead Man: Soviet era post-apocalyptic dirge doesn't insist on the bleakness that is apparent enough to need no comment. The cause of the cataclysm is, interestingly, operator error. Final scene with the children marching off into a puzzling future, in anti-radiation gear to the strains of Mozart's Masonic Funeral Music is both inspiring and heart-rending.