You're young and planning to be there for a few years. Fuck all that noise about moving to "quiet" outer borough neighborhoods or suburbs.
Live in Manhattan between the Brooklyn Bridge and 14th St. That gives you plenty of different neighborhoods to choose from in terms of character/style, price, convenience, etc but you'll be near most of the main nightlife areas & good food/shopping w/o all the stupid midtown/upper x side BS.
Maybe consider N. Williamsburg in Brooklyn if that's your scene, and only then if you're near the main drag.
Other Brooklyn neighborhoods don't make sense.
Park Slope is fine but mostly 30-somethings or boring library science grad students. DUMBO is a made-up neighborhood for Wall Streeters & real estate brokers who want to wear funny glasses on the weekend and go to art galleries exhibiting Soho rejects. Cobble Hill, Carroll Gardens, Ft Greene, and Greenpiont have cool spots especially food-wise but you gotta know the area well and it's not really worth the effort until you've been in NYC a long while. The rest of Brooklyn is either inconvient or "sketchy"-seeming for someone not accustomed to real urban living.
As for newcomers to other boroughs:
Queens is for immigrant families & poor anime nerds with yellow fever.
You're way too white for most of the Bronx.
Staten Island is the armpit of the city.
Re: prices don't listen to some of the nonsense above. $3-4k will set you up just fine. You can find a good quality 600+SF 1-2 bedroom apt for that much AND in a good neighborhood, AND convenient to the subway if you a) do your research b) know what you want and don't waste time c) be persistent and d) haggle like a motherfucker. You could even stretch $2500 that far but don't expect that your first go round because you won't know what you're doing.
Just shack up with someone for 3 or 4 weeks and hit the pavement. Plenty of great deals out there and
it's only getting better. You don't need a fucking doorman unless you're a pussy and need someone to wipe your ass. And real estate mgmt companies are for suckers. Find small-time landlords and rent direct if you can.
If you have to go through a broker (most of whom are total scum), which 90% of newcomers usually do, negotiate the fee down to 10-12% and make the landlord pay it. It's fast turning into a renters' market, so hell, negotiate the rent price too, and try to get 1-2 months free up front.
Anyway, just do it. So much awesome shit to do, great food, endless parties, HOT chicks. Assuming you've got the scratch to make the move (plan on $15k to cover everything and really get settled), you won't regret it.
