Considering geographical and weather conditions as well... plate tectonics, volcanic activity, risk of tsunami, risks of hurricanes or tornadoes, etc.
In that case, Australia. We're sitting in the middle of a tectonic plate, we've extremely low chance of volcanic activity, and we're a fair ways from anywhere much. We do have some flooding problems in some places right now, and the northern end get the occasional cyclone, but there's a hell of a lot of Australia to choose from, so you can easily avoid those areas. Head inland right to the centre and about all you need to worry about is food and water

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Also, in the event of a zombie apocalypse, you'd pretty much be golden if you get out of the cities and go bush. If you only count the contigious states, AUs is a similair size to the USA, and we've got around a tenth of the population, so there's plenty of places to hole up. In the event of a nuclear or biological apocalypse, much the same goes (as long as you get out before things go to hell).
At some point in the future our vast quantities of land and resources may start looking rather tasty to some of our neighbours with increasingly dense populations, but that's a long way off yet (and would likely require some major destabilisation).
My basemant.
Come live here! Lots of sweets and food, locks on the outside and inside, bombproof walls, shackles so you never have to worry about tripping up and hurting yourself. Plus it is in England so there is pretty much no natural disasters.
On the other hand, there are Chavs

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