I would wish that two thirds of the human populace would die/disappear, preferably without huge nuclear clouds, most of the electronic stuff in the world(global EMP) would become useless and the survivors would be distributed around the globe evenly, and give a good head start(equipment, skill) in agriculture.

after a rough beginning the globe would be a much happier, cleaner and more natural place for however is left.

This of course after I have seen the last season of Lost.