Posted this in another thread a few months back but here you go...
Absolutely love NYC. My advice - don't bother visiting the statue of liberty. Waste of time. You spend hours and too much money doing it. Just get the free staten island ferry instead that passes it. The view is perfect for the photos etc. When it stops, immediately get back on the next one and head back to Manhattan for a second view, as there's nowt really on Staten Island. You can spend more time doing the interesting stuff then!
Oh, and go up the Rockefeller, not the Empire state. MUCH better views of Central Park, and you also get the view of the more interesting building - the Empire state :)
Rent a bike in central park, have a cycle around it if the weather is nice. It's great fun. I enjoyed the American Natural History museum, the 9/11 memorial museum is a must too. Sobering, but stunningly well put together. We had one spare thing left on our city pass so we went into the catchily titled 'New York City's Intrepid Sea, Air, & Space Museum' - we enjoyed it! Surprised us tbh.
Our absolute favourite thing we did though was do a huge walk taking us from Little Italy, through China town, down through the financial district (wall street etc), then on to Battery park and walked up the west coast of manhattan. A stunningly fun/beautiful walk that takes in *loads* of unique parts of manhatten. Hugely recommend it.