I'd add one criteria to your list, which obviously you have considered, too - language. Even in a country where "everyone" speaks your language as a second or third language, it can be terribly isolating and occasionally dangerous not to understand the local lingo.

It sounds as if you are pretty widely travelled. If no city or country really jumps out at you yet, it may take a few more years of travel to find your dream spot. Sure, your home country may suck, but it's really discouraging to move someplace you had high hopes for and find out after six months or a year that your new home sucks, too, just in different ways.