I loved Earthquake - not seen it for years though.
I watched The Day After Tomorrow recently as an in-flight movie (which is rarely the best way to see a movie) and was gripped by it. So I have to have it up there at the time being.
Can Independence Day be classed a disaster movie? It was a bit of a disaster for mankind - I liked that one also (same people who did The Day After Tomorrow i think come to think of it).
And I have to say, as much as it has become a bit of a tired cliche and if it came on the tv I doubt I'd watch it, I have to say Titanic, thinking back to the impact it had when first seeing it in the cinema - there surely wasn't a dry seat in the house.