New York is really fantastic. The sightseeing is endless - as is the shopping.
I travelled with my Partner and our 5 year old Son, so shopping wasn't our biggest priority. As it was our first time in New York, we decided to stick to the sights. We did the Downtown, Uptown & Brooklyn bus tours which were really good and it helped us to find our way around the city. We also took the ferry from Battery Park to Liberty & Ellis Islands. The view of the City looking back was brilliant. When we booked our tickets for the Tour Bus, we also got tickets for a cruise on the circle line, which took us up the Hudson River under Brooklyn & Manhattan Bridges. We opted for the later cruise at 4pm and the sunset on the way back was spectacular.
Our Hotel (Novotel) was right at Times Square & the Broadway Theatres, which was brilliant and also within walking distance of Radio City Music Hall and the Rockefeller Centre. The Rockefeller Centre is well worth visiting, with amazing views of the city from the "Top of the Rock". In the winter there is also the added bonus of the Ice Skating Rink in Rockefeller Plaza. There is a second rink in Central Park and you can't go to New York without taking a Horse & Carriage ride through Central Park.
As we were looking for a more Family orientated trip, we visited the Central Park Zoo which is small but really nice and very cheap and we then walked across to FAO Schwarz (Toy Store) which is opposite the Plaza Hotel (Hotel used in Home Alone). We did all the other sites too like the Empire State Building, Chrysler Building, Macy's, Ground Zero etc.. The thing I noticed most about New York was that the locals were so very friendly and that alone would ensure my return.