New York... having lived there for five years, I realized you can do ANYTHING there, except legally own a gun. Toronto seemed like a nicer place to live, but NY is definitely #1 on my list for its awesomeness (and Brooklyn, which brings the other boroughs up a notch on my list). All my sentimental childhood memories are in Pittsburgh, but last time I was there I realized my neighboorhood has become the hood after some kid tried to steal my $35 laser pointer.
Still, I'd rather live in the country than in any city. More than half the world's population now lives in cities - let them go, more room for the sane.