Statue of Liberty / Ellis Island
Best time to visit in the AM, first or second ferries because the line can be long, please note that this requires at least 3 to 4 hours otherwise we are in a rush. $ Entry Fee.
Observation
Spectacular views of the city, as much as I adore the Empire State Building the line can be long, I often suggest Top of the Rock. Night visits it seems the stars about below your feet. $ Entry Fee.

Brooklyn Bridge
Something to behold, walking, it is a lovely connection to some lovely neighbor-hoods, sharing its history and lore can be had on either side of the East River. Don't miss it.
Washington Square
Not the only town square but one of the special ones. So many sites like this throughout the city. A part of Greenwich Village it is a starting place. It is a happening spot.
Food
With 1000s of choices, planning a meal and coordinating a tight schedule eating is a necessity. Price point is subject to the location or the demand of the spot.
Chinatown
One of the many cultural destinations in New York City. Downtown near Little Italy.

9/11 Memorial
Passes are required, they can be obtained the day of; however, subject to first come, first serve, not a guarantee. ID may be requested. FREE, suggested donation.
Central Park
843 acres of green space right in the middle of the city is a haven and a delight for locals as well as visitors with so much to see. Truly need a guide for this particularly if you have limited time.
Musuems
NYC museums have lots to offer. Some ask for a donation and others have a flat fee, there is something for everyone. It is so easy a museum, a nice meal, and theater. A day in the city.
Theater
Live entertainment is the pulse of the this great city. It is up to you as to how much you pay, the streets themselves provide some of the best of the theater, you just need to know where to look.
Shopping
For some it is a sport, and like a sport, timing and pace are crucial. Understanding the landscape, and the zones prime for retail therapy is important.
Wall Street
One of the most historical streets in the United State. Federal Hall, New York Stock Exchange, & the Trinity Church.