Where are you working right now? The subway in NYC is quite convenient but walking is even more so. Wintertime in NYC can get pretty chilly though so you'll want somewhere close if possible.

I'm in the city now for a 5-week gig, tried to get into the ExecuStay in Chelsea but it was booked up completely, so I ended up with a place from Signature Properties (The Atrium, on Bleecker) - not bad at all, though I would have loved the Marriott points.