Let's be honest-no event that can be accurately referred to as an apocalypse is going to be any fun, but as the movies have taught us time and time again, some apocalypses are worse than others. If you had to choose, you might pick something like what happens in "Deep Impact", where there's at least some semblance of a happy ending. But with the following six apocalypse movies, there's very little hope for happy endings.
In most apocalypse movies, humanity bands together in order to survive in the new world that is born from some global cataclysm. That doesn't happen in "The Last Man on Earth", and you can probably guess why from the title. Vincent Price thinks he's the last human in a world where most of humanity has either been killed or turned into killer vampire zombies. The truth ends up being much scarier (and deadlier).
The J-horror film "Pulse" is short on details, but incredibly long on apocalyptic dread. The result is a movie that is plenty creepy BEFORE the end of the world happens. Once it does (because of something to do with ghosts possessing the internet and driving humanity into suicide), it's probably the creepiest movie apocalypse of them all. It's not a nice world to visit, so just imagine living (or dying) there!
Some apocalypses at least offer the relief of not having to do anything anymore, but in "The Terminator", once most of humanity is obliterated by a nuclear strike, the work is only just beginning. Now it's time for humanity to rise up and fight against the machines, utilizing time travel to preserve the last hope of humanity, etc. What a pain.
"Invasion of the Body-Snatchers"
Most Robert Altman movies take place in a pleasant place. Not "Quintet", though, which depicts a world in a nuclear winter, where the few remaining survivors of a nuclear holocaust pass the time by playing a murderous game called "Quintet". The rules are incredibly complicated, but suffice it to say that it involves a lot of death, and you have to play whether you like it or not.