For me it is impossible to answer the question

For me it is impossible to answer the question what are the best places in the world to live.  I think it depends on who you are what you are looking for and what things do you need in your life to be happy.  Do you need a common language where you are going?  How about family and old friends?  Weather, rain, climate,medical and all sorts of things a person should consider. 
I made a list of what I wanted and needed in a new country.  I had traveled to 36 countries when I was a younger adult and frankly I found many different countries I thought I could be happy in.  I settled on Panama for reasons that were important to me.
A democratic country, tropical, good services for medical and dental, close to the USA, good cost of living, two oceans with just over an hour driving time between them, good shopping and restaurants, golf, scuba diving, fishing, mountain climbing, availability of different temperatures within easy driving distance, sports, movies, lots of expats (however I don't hang around expat groups much), not much violent  crime and an easy going tranquil lifestyle.
For me Panama is one of the best places in the world to retire.

Best Places In The World To Retire