I haven't really done that much travelling to really have an informed opinion of any of the places I think I'd like to move to. Plus, I've only really stayed in a city for a few days or a week. Outside of North America, I found Ceske Budejovice a really interesting place. Ditto Salzburg/Eugendorf, though Eugendorf was a little too quiet for my liking. Vienna didn't really leave a good impression on me; it stunk like shinguard my whole stay there.
In Canada, I really really enjoyed my stay in Ottawa. It seems to be the right mix for me: enough elements of big city and small city to make me feel at home
I'd like to experience Calgary more. To date, I've only been there a grand total of three days, but I've loved every single second of it.