I would recommend goint to White Plains Westchester County KHPN. I just flew up to NYC over Thanksgiving and the airport was nice, low-IFR approaches, and Panorama FBO was terrific! I too looked at TEB but it is very big and expensive. The Linden airport seemed OK but looking closer it doesn't have a true IFR approach and doesn't have an IFR departure. If the weather is bad, which it will be this time of year, you may not get in and you'll certainly never get out IFR. Panorama gave us a ride to the train station (5 minutes) and we took the express to Grand Central (~20 minutes). Total piece of cake. When we returned they picked us back up, no hassle and no charge (we did give the line guy a healthy tip). As a bonus the FBO had drinks and snacks for the kids, no charge.
As for routing. GOOD LUCK! I fly over NYC quite often and I've never figured out the magic. Just file direct and plan on multiple airborne clearance changes.