North America would be my favorite. In terms of political stability, social and economic freedom, and general opportunity it is unmatched.
Western Europe has it's merit's too, but higher costs of living and more stringent regulations push it behind the USA, Canada and Mexico.
Eastern Europe and much of Asia suffers from political instability, widespread poverty and famine, and certain cultural remnants spoil the attraction for me.
Australia seems OK, but an amazingly high cost of living and numerous global inconveniences sabotage the alluring powers of it's natural beauty and laid back atmosphere. Oh, and drought and wildfires.
South America...well, it has a booming economy, strong trade connections and interesting scenery. Sadly it is also vastly controlled by corrupt governments, drug cartels and many other forms of sadistic rule. Doesn't seem to be a very safe place to live.