1. Empire State Building
I absolutely love the Empire State Building. I visited at night time, but I think it would be better in the day unless you enjoy seeing just a bunch of lights. And don't visit in the evening at -12 degrees! But still, I had a great time taking in the views and learning about the history of the building while queuing. The Empire State Building shouldn't be passed over as 'just a building', it is a New York icon!
2. Grand Central Terminal
It's not just a station, this place holds so much history. I visited on a 'pay-as-you-feel' walking tour and it was worth every cent of the twenty bucks I gave the tour guide. The history of Grand Central and the buildings surrounding it is fascinating and well worth the visit and a tour.
3. The Statue of Liberty
I visited in winter and therefore had a nice and warm 24 degree climb to the crown and very few people and little lines. But there was a lot of snow on the ground and ice coating the banisters. Then I lost my beanie and got to take a run back up the tight curling stairs. I wouldn't recommend this is you are a big person as the stairs are quite narrow and a confined space. But other than that, you can't visit New York without a visit to the statue. And the best photos are definitely taken on the island.
4. 9/11 Memorial and Museum
No one will ever forget this day in 2001 and visiting the museum is a very moving experience. The memorial is beautiful and the museum holds a lot of eye-opening information. And to watch the security footage of the hijackers is mind-boggling. If 9/11 touched you at all, then it is well worth a visit to this museum.
5. The Metropolitan Museum of Art
Not only does the Met hold some of the world's most beautiful pieces of art and history, the building itself is magnificent. While there is a 'pay-as-you-wish' fee, it is essentially a free or very cheap place to spend your time in whilst in New York, and perfect for the winter months to escape the bitter cold and soak up some culture.