Other people won't share your preferences, so rather than an arbitrary list of cities, here's a process for finding your own. First, given your goal of "[parti

Other people won't share your preferences, so rather than an arbitrary list of cities, here's a process for finding your own. First, given your goal of "[participating] greatly in local business and community," use language as a first filter. This question will either eliminate or open up most of the world: "Am I willing to spend 3-6 intensive years to learn a new language (and not be very effective during that time)?" Near-native fluency isn't required to live somewhere, but it is basically required to make an impact there outside of any expat bubble. Second, from that scope, pick any 3 cites that meet your cost of living requirement and live in each for a month. Airbnb makes this relatively easy. Aim for significant differences - continent if possible, city size, culture, weather, similarity to your situation now, etc - between the 3. The specific 3 cities matter less than ensuring you experience a month in maximally different situations. Use what you like and don't like at those places to decide where to live/test next. After living briefly in 1-3 more places, you'll either have a strong, informed opinion about what you like (and probably a favorite place), or an unexpected result, like that you actually enjoy moving around, or aren't happy anywhere, or don't want to leave where you are. (Source: I did something like this, though not with the goal of relaxing)