There is the 1994 American Broadcasting Company mini-series The Stand. Stephen King was the executive producer and while I loved it, not everyone does. Some folks hated it.
There is also the 1959 Stanley Kramer film On the Beach. While OTB is a very good movie, I seriously question the central premise, the extermination of all animal life due to an atomic holocaust.
World Without End is a 1956 movie from Allied Artists, that is very low-budget, but is nonetheless a surprisingly good movie.
I am surprised that nobody mentioned these.