In addition to Ippudo, Totto Ramen is also a great noodle shop.
If you enjoy stand-up comedy, you really should check out the Comedy Cellar. I go there every time I'm in NY. They have a surprise guest comedian every night and it's almost always a big name. Once it was Chris Rock. The most recent time I went it was Aziz Ansari. It's also cheap. Tickets are only $12 and there is a two drink minimum but beers are very reasonably priced - $5 I think. Reservations are necessary but one night beforehand is really all you need to do.