I would pick Canada, because it's close to the U.S. (making it easier to move there), and I'd have the right to marry.
Lisbon or Istanbul are two places I just adore and think I could live in happily. I haven't been to Buenos Aires yet, but everything I have heard about it makes me want to spend at least a year or two there.
Over the years I have wanted to live in a number of different places. The list has remained pretty much the same actually lol. - New York City - London - Ireland or Northern Ireland (I have family in both places) - Australia (Sydney, Melbourne, one of the big cities) - Sweden (Stockholm or Gothenburg, most likely) I'm a city girl, so wherever I end up, I'd like to live in or near a big metropolis. That's not to say that I wouldn't eventually move to the countryside or suburbs, but in general I like the pulse of city life.