I haven't been in NYC for that long but I've found that the well for film in NYC is pretty deep and you can really find anything you are looking for on a given night. Obscure, Foreign, Indie, Cult Classic, whatever.
Screen Slate is a good resource to find whats playing where all around the city.
I would also suggest following a lot of the theaters on ig and they will have posts about showings that might pique your interest.
Spectacle and Film Noir are pretty cool screening rooms in BK that are pretty low key and DIY if you are looking for an interesting night out.
Finally, getting a membership to metrograph, ifc or film forum is a good option if you go to one of them and like it. Reduced prices go along way if you are going to a theater pretty frequently.