See a Broadway play. Any play, it doesn't matter. I saw
The Little Mermaid and almost died from the fantasticness (but that was for the benefit of my inner 5 yo...you might wanna try
Wicked or something
). The Empire State Building costs 19 bucks, but for the view you get at night when the whole city's lit up, it's worth it. Times Sqare is a must, but I warn you, it's full-on sensory overload after dark. It's so bright and loud and people, smells, and sounds press in on you from every direction. Even just to walk around and shop or go to D&B (which you could do anywhere) is a major something. If you go to Lady Liberty BUNDLE UP, it's so windy on that water, we froze half to death before we even got on the ferry. And yes, I've never had a desire to go see Ground Zero, but I'm glad I went. It's one of the most moving things you'll see...much more than a 16 acre-ish hole in the ground.