I have no idea how hard it is to get into. My mother got here by marrying my father, eons ago. I was born here.
I am only talking about America because it is what I know the most about. I have lived in Germany, a long time ago. I have lived a number of places in the US: Georgia, Texas, Kansas, Washington (state, not DC), and both Southern and Northern California. I also have driven through quite a lot of the US and was hoping to pursue a career in urban planning before life sidetracked that goal. So I have taken classes related somewhat to city planning stuff and spent time on an urban planning discussion board. I also am not happy with where I am currently living and hope to move at some point.
Some of the resources I use for assessing potential places to move:
bestplaces.net
http://scorecard.org/
http://www.city-data.com/
websites for some of the restaurants and grocery stores I like
google maps
weather.com
Some of my criteria:
cleaner air than where I currently live
more walkable, transit-oriented community than where I currently live
~50,000 -- 100,000 population city within about 2.5 hours of a major metropolis
cost of living similar to here or cheaper
some must-have amenities (in terms of food mostly)
No or low state taxes
At the moment, I am considering moving to Cheyenne Wyoming -- assuming some miracle or twelve makes it possible for me to leave here and go someplace of my choosing. I was considering Port Aransas Texas at one time but the opportunity never came up and that notion has since died.
Good luck with this.