My sister and her husband run TheaterSports of NY. You might look on line and see if they have a show while you're there. Or you could go to something off, off, off Broadway. I've seen some good plays at very little $$. Other things to do would be the USS Intrepid museum, stop at the Little Pie Company for an excelent piece of pie, loads of museums, Central Park is great. We haven't done much as far as evenings go but you should be able to find loads of things. Have fun