Best Answer - Chosen by Voters
You've been to NYC several times, but have you been here during Christmas? I think it gets nicer at this time of year, although it's super crowded.
You don't say how long you plan on going on vacation. If it's for a few nights, why not spend 2 nights in NY and then go up to Boston for a bit? It's a relatively short ride between the two cities (about 5 hours by bus, even shorter by train).