Speaking as a current banker, all three are going to give you a shot at the fiance world.
NYU has the closest connection as it is based in NYC. That said, local firms will expect constant interviewing whilst there is more breathing room for SOM + Sloan candidates.
Also NYU has a reputation for cutthroat and more focused job searching. Expect to spend less time getting friendly with your classmates and more trying to get an edge in your group interview style. You are gaining a city with Stern, but losing the community you find particularly at SOM and to a lesser extent at Sloan.
Looking to Boston, Sloan is a heck of a school. It is going to be quanty and that school reputation will always be in the back of someone's mind when you mention MIT. You have opportunities to network with engineers and perhaps play around in the startup space.
We know better, but outside of finance the name Yale carries heavier weight than NYU or MIT, despite SOM being the ugly duckling of its parent university.
Down to brasstacks -
Sloan: If you are looking to finance, everyone in banking/money management knows MIT is hot ****, especially on the quant trading side. Good network, but tech/engineering heavy.
Stern: Lots of finance exposure, less community, not as fun (unless you are dying to move to NYC).
SOM: Carries the ivy league reputation, strong community, fewer finance placements (because of lack of interest by students) but less competition for the openings.
If trying to break into finance, my choice would be Sloan. Stern gives you lots of options but you fight for them, whilst MIT/Yale will help you open doors for the rest of your career.
Best of luck with the decision, you've got a great problem on your hands.