I lived in NYC for one year for a job - March through March. I got to see the city as it changed seasons, tourist numbers, and attitude (I swear people get more pissed off the closer it gets to winter, heh) and it was a blast. Kind of.
As a food person, the abundance of delis everywhere just made my day. I ate in as many as I could and I put on 15 lbs
Most nights I was too tired to cook so I'd buy dinner out and it was always something new and usually delicious. I loved that. Sometimes I would just take the subway and ride to somewhere I'd never been before, look around, and go back. It was remarkably easy to be single in that city because I had so much to do and never felt lonely. Most of the time I spent in my apartment though, because I didn't make a lot of money. I would read or talk to friends online and listen to the cars honking below and the sort of 'buzz' you hear from all the electricity in the air (literal electric wiring, not NY having a dynamic energy or something).
I have to say that part of the reason NY was so great for me was because I knew I only had a year to soak up all the culture and atmosphere and do everything I wanted to do. I could tolerate the cold in winter, the sweating in summer, the post-work exhaustion, the tourists, the crowded subway cars, the living off coffee because it's all you can afford, never having anywhere to yourself...because I knew it would end. However, by the end of my year, I was starting to get really tired of it.
I did not make one actual friend in New York, though I had a few coworkers I would hang out with. They didn't seem to have friends either. I think the only way to make friends in NYC if you're from out of state is to join some kind of scene or class outside of work. I could not imagine living in NYC permanently and trying to find a partner and settle down and have a normal life. Way too intense there for me. I don't like suburbia so that would be out. My favorite parts of NYC were the more family-centered parts of Brooklyn and the Bronx, that's where I would live if I had a family. But my sincere kudos to people who can live in Manhattan and make it work, my hat is off to you.
If I had a bazillion dollars I would buy a place in New York and live in it for a couple of months a year. but then I'd come back to New Mexico, happy with my quieter life. Plus if I had a bazillion dollars I'd have to socialize with the NYC elite - no thanks