I've lived in three places.
Was born and raised on Long Island. Definitely do not like living there. Suburban sprawl (not as bad as the Los Angeles/Riverside/San Bernardino area - that's the worst suburban sprawl I've ever seen, depressing), but still crappy public transportation and car-dependent. The age of the town meant that it did retain some of it's old charm, which I do like. I live close to a LIRR station, so New York City is just a train's ride away, and everything that it has to offer.
I then lived in Washington, DC for a short while. Cool city, if you know where to look. The tourist center of the Smithsonian and the Mall gets boring after a while, but after being there for a while, you start to find the good places in Georgetown, the GWU area, DuPont Circle, and stuff. The state the southwest and northwest are in is depressing - although the northwest area is seeing major improvements recently (I lived in the NW). Public transportation is pretty decent, could be better, though.
I now live in San Francisco. Awesome city, great public transportation, lots to do and see and do, and many places to eat. I loved (and am loving) my time here, but can't see myself living here for longer than 5 years or so. The rapidly worsening homelessness problem, and the worsening attitudes of people is dragging the city down. I have to see it everyday, living in the Tenderloin. And the skyrocketing cost of living isn't cool, either.
I'd love to live in New York City proper one day. Awesome public transportation, has everything you could want in a city. The only negatives about NYC is the weather (I do not like ice, and I do not like humidity. NYC has a lot of both in their respective seasons. Yuck.) and the i-n-s-a-n-e crowding certain times of the year (try boarding a subway train in midtown during a event, like the July 4 fireworks. A few times I even had to go back out and walk, or find another station, because people are so retarded that they packed the subway cars so tightly that it just won't move until some people leave. Jeez.)
I wish I could be a nomad, living in different cities all over the world. I've visited London and Paris, and loved it. I wish I could live there for a year or so, to really get a feel for the city. You know, that knowledge and feel of the city that you just can't get from just visiting there. Money, and other stuff prevent me from easily doing that, though.