The right answers is ..... the best city (to live) is the best place for you, your family and goals.
Even knowing I like several cities in US, I wouldn’t move away from Canada (due to political, safety, education, financing steadiness and health care reasons) but I would definitely invest there as long it matches my criteria.
I went through the answers and unfortunately most are biased as people are promoting their own business (which is understandable) so remember one important thing .... you can invest in a cash flowing place without having to live there. That’s why PM companies exist. (It doesn’t matter if the city is good, bad or ugly as long makes you money)
My approach is simple ..... invest for financial gains (anywhere) and live in a city that provides the lifestyle I am looking for. (if you can combine both even better)
I live in Kelowna (possibly one of the best places to live in Canada) so we invest around here because regardless what happens in the world, this piece of paradise will always be a highly desirable place.(This region has short winters and hot summers, 128 wineries, orchards, more than 19 golf courses, 2 ski hills, several lakes, great outdoors, etc.)
Note: Our latest investment is in Victoria, BC but in US I would consider Arizona, Texas and Indiana.
Happy investing
Edison