I think the only way to find out if you'll be happy in a city is to move there for a while and see if you like it. Cultural affinity is very personal; you'll read all sorts of opinions from everyone on HN, but they won't tell you anything about whether you will like it.
FWIW, I've lived in Boston and Silicon Valley and have a number of family in NYC. I can't stand NYC - it's too busy, no greenery (Central Park doesn't count, it's all man-made), and generally feels like I'm living in a concrete cinderblock. I really liked Boston, but the culture is just a little bit too conservative, and I didn't feel like there were any professional opportunities that didn't involve paying my dues for 30 years while the world moved on around me. Silicon Valley has a wonderful openness to new ideas and a nice "seize the day" mentality, but everybody seems just slightly insecure about how their next-door neighbor just sold a company for $100M, and there's a big unhealthy competitive dynamic behind the surface. SF (& Berkeley) is charming but also has a slightly ridiculous lack of self-awareness - there is a huge population here who really values their quality of life but doesn't realize that their actions are the cause of all the things they complain about. (Witness all the folks who love their iPhones and Uber but hate the techies who make them, who protest rent increases but won't allow new housing construction, who prevent the state from raising taxes and then wonder why California is in perpetual budget crisis, and who hate the Comcast monopoly but won't allow any new fiber lines to be laid.)
On the whole I think Silicon Valley is probably the right place for me, but I still wish I could find a place with the openness to new ideas of Silicon Valley but without the competitiveness and greed.
Your mileage may vary, but anecdotally I've lived in all three and NYC wins by a really wide margin.
That said, Seattle is a lot more economical - salaries are a tad lower than SF or NYC but more than made up for by lower cost of living (though this is changing).
