Well, that is a tough one because you would have to seek out one not-so-affected by propaganda and civil unrest, but also at the same time one in which you could realistically apply for citizenship. Ideally for me, it would be somewhere like either New Zealand or Norway. My roots are in Norway but too far back to allow me immigration. New Zealand has risen above much of the ugliness, but they too, have suffered as in their church shooter.
In the past, I considered Ecuador as a possibility. They speak very straight spanish with little dialect or slang. The almighty American dollar goes a long way there. But if one were to consider it in old age, one would have to consider hospitals and the like. Those don't stack up well .
Certainly, if I was a millionaire, somewhere in the alps of Switzerland might be something I would consider. Somewhere where life moves slowly and the outside world doesn't seem so big and intrusive. Where nature is but a heartbeat away in its beauty within reason, of course, in taking proper precautions, but you could not help but even in something as simple as looking out a window, thank your lucky stars.