Min ...
When you mentioned "in the world", I would rule out Europe (too cold for me) and Africa (haven't been to many places there but not where I would choose to go). Asia, maybe. Hong Kong was interesting before China took it back with the political crap.
Australia? Maybe. Never been there but it may be interesting but they drive on the "wrong" side of the road.
South America? Probably not.
Caribbean? Probably not. Either way too expensive or too much crime.
Costa Rica. Yes! Very stable politically, great food (especially seafood), excellent health care, relatively low prices, a huge number of Americans and Canadians there and overall a very nice place. Very good beer for about one dollar per liter (quart).The Caribbean side does have more crime than the Pacific side. There are some very, very beautiful areas there, especially on the Pacific side. A lot of English is spoken there with so many ex-pats.
Easy flights to the US from the capital San Jose to most major US cities.
The people are extremely friendly.
I would definitely consider living or retiring there.
Rub a Dub