Where to eat in New York during Christmas and New Year's?

An interesting, fairly recent phenomenon in Manhattan is the proliferation of Belgian restaurants. A nice one on the Upper East Side is Brasserie Magritte. Any Belgian place is going to feature beer prominently; Magritte has a fine selection, especially the Belgian specialties like sour ales and lambics. Try the pommes frites.

For something really festive (not cheap), I like Kings' Carriage House. Dinner is excellent -- especially any kind of duck -- but the real draw is the decor, which is 19th Century urban rustic (if there is such a thing). It's as nice a space as you'll find in the city.