Yeah, depends on the firm. Midtown east is pretty difficult to get to from Upper West Side (UWS) on the subway. I like midtown east (probably above 50th) for proximity to work, relatively nice apartments, and good availability of things to do. UWS is affordable for Manhattan, and offers reasonably decent access to downtown/west side firms (cravath, skadden, S&C, Cleary, Ropes, Willkie, Milbank). Midtown East, UWS, and UES around 1st/york are generally more affordable than the other places to live in the city.
Here's how I think of neighborhoods (focus on manhattan, a little bit of brooklyn, queens, Jersey. Leaving out Bronx/Staten Island/Long Island/Westchester, since I don't go there or know anything about them)
Brooklyn:
Williamsburg: difficult to get to from most firms, full of hipsters
Brooklyn Heights: accessible for east and west side firms (4-5-6, 1-2-3), families, expensive (for brooklyn)
Other Brooklyn areas: Generally cheaper, depending on area. I could be wrong, but I've heard good things about DUMBO, Carroll Gardens, Boerum Hill, Park Slope, Greenpoint. All may have accessibility concerns.
Manhattan:
Financial District: bro-ish, accessible, high rises (so dollar-value expensive, but lots of amenities)
Battery Park City: High rises, cheaper than other financial district, feels like a neighborhood, but requires a long walk to the subway
Tribeca, Soho: $$$
Chinatown: Cheap, accessible, likely to have rats in your building. Also, canal street is a major negative (crowded, touristy, dirty, too much kitsch being sold on the street).
Lower East Side: Also full of hipsters. Public transportation is difficult. Rapidly gentrifying and getting expensive (hipster influence).
East Village: NYU hangout. Lots of bars, some puke in the morning. Relatively affordable, but usually walkups.
Central/West Village: expensive, trendy. 80 Marc Jacobs stores on Bleecker, people to match.
Union Square: Meh. Has a Whole Foods and Trader joes. Transitional area between NYU and the Gramercy/Flatiron/Chelsea areas. Also, Union Square is where many protests/street performers gather. Positive or negative, depending on outlook.
Meatpacking district: $$$, and also dirty.
Gramercy/Flatiron/Chelsea: Fairly expensive. Gramercy is the most genteel, transitioning gradually through corporate/shopping stores around 5th ave, and into chelsea which has a sizeable gay community.
Stuyvesant Town/Peter Cooper Village: Lots of bros, but fairly affordable.
Kips Bay/Murray Hill: lots of bars; this is where the stuy town/peter cooper people come to hang out. Not sure what that means?
http://www.toniceast.com/media/tonic.html
Midtown: Lots of office buildings. Probably don't want to live here. Boundaries are a little bit uncertain; may include Herald Square area up to 59th street. Lots of businesses, lots of tourists. Some ok apartments to the west side between 23rd up to 50th, depending on what you're looking for, maybe on the east side as well.
Midtown East: Residential again, good for east side law firms, not great for west side, see above for more.
Hell's Kitchen: Good for west side law firms (Cravath, etc.). Excellent food. Suffers somewhat by being on the edge of the theatre/times square areas.
Lincoln Center/Midtown West: Some Trump buildings here; may have nice apartments. Growing in price.
Upper West Side: comparatively reasonably priced, decent transportation around 2-3 express stops. "neighborhood-y" feel (though not quite as much as Brooklyn and West Village).
Upper East Side: More expensive, more upper crust. 4-5-6 is the most crowded train in the city. Good for east side law firms.
Harlem: Gentrifying pretty rapidly. Pretty good food. Very transitional (danger levels change by street/avenue).
Queens:
Long Island City/Astoria: Affordable. Pretty good train service through east side law firms and, to a lesser degree, west side law firms (follow the N-Q-R).
Jersey:
Hoboken: Cool and young. Can be hard to get to, especially if you live far from the PATH train. (Also, keep in mind that PATH service is limited and requires transferring to the subway, and also, if you get out at WTC, has a nasty walk along Vesey street)
Jersey City: Lots of high rises and good views. Also cheap. The price? Have to live in Jersey, and also can be hard to get to (especially for midtown firms).