I live in Ireland, besides the absolutely shit government its a really nice place to live Also , I really would like to live in Japan for a few months of my life
I find it difficult to determine which country is the best to live in, instead it is much easier to determine where one would not want to live. My point being that there are many countries that suffice to what we as people have ended up desiring in government (to a certain degree with margins of error).
It's too difficult for me to claim that the US is the best to live with it's issues, similarly it can be said the same about other nations. Personally, I think the sooner we break down the "borders" dividing people we will see more dramatic changes global wide. An example being how much of an impact globalization has held on an economic, cultural, and political level. Whether people like it or not it will be an inevitability and overall it should bring some progress.
Anyways, back onto topic, I will likely spend the rest of my life within the US unless other circumstances interfere or present themselves.
I don't think there really is a "best" country to live in because we are all entitled to our own opinions. However, I would really love to live in Ireland/UK area.