I've been a few times - would definitely recommend taking the ferry out to see the Statue of Liberty up close if you can. Also loved the Top of the Rock - amazing views! Times Square is a must. I remember going up in the Empire State Building in high school - it's iconic.
Carmine's is awesome. Katz's Deli is another favorite. The food trucks are amazing - the Halal guys are a favorite.
The 911 Memorial is on my list but I haven't made it there yet.
Not sure when they will start putting up holiday decorations, but they are incredible. Just walking around and seeing all of the window displays is super fun.
I hope you get to go!