If we care about how happy people are in their country then maybe we should look at http://www.oecdbetterlifeindex.org/ There is no clear number 1.
This just in, according to songs written by Jim Morrison the west is better 100% of the time.
Other people who posted here claim nominal GDP is how you compare nations, but that's got problems, too: Is US overspending on health care really adding to GDP? Is military spending, Homeland Security, cops, prisons, adding to GDP, or those costs and drags on our wealth? Is financialization adding slushy numbers to GDP?
Look at the US productivity numbers. Impressive! But is our spending on health care really productive? Military? Etc. There is a ton of fudge in US economic numbers.
I'm sure China's numbers, with the state enterprises, have a lot of squish to them, too. But the US is overtly fooling itself in many ways.
The same things seems to happen if you put in the sort of priorities other countries are generally believed to hold (so put in the environment, satisfaction, work life balance and so on and the Scandinavian countries leap to the top).
So if there is any truth in the cliches, countries do seem to optimise for what is important to them. Which I guess is what you'd hope happened.
As an aside there doesn't seem to be too much you can do to stop Australia being a great place to live - they don't have a slider for "Deadly animals".
Australia has poisonous snakes and America has grizzly bears -- only New Zealand can claim no deadly animals.
[1]: http://www.urbandictionary.com/define.php?term=Kiwi&defid=20...
I don't think that I'm imagining that Australia has more species of lethal animals than any other country.
EDIT: Just to be clear, I'm not saying Australia isn't a great place to live. I've only been to Melbourne and then only for three weeks but it seemed great. There are just lots of things which can kill you there (though the Australian's have naturally got very good at stopping that happening).