Costa Rica
Last time I was there an American pensionado told me that the gov't there did not tax pensions. Great weather, easy access back to the US, pretty good infrastructure--health, transportation, etc. Well educated populace for the most part. Crime in SJ not much different than in any other big city.
Lots of Americans retiring there.
It has been 10 or 12 years so I may have dated info.
WW