I went last year and went to Macys, Times Square, Staten Island Ferry, Wall Street, helicopter ride over Manhatten (booked over the internet), Greenwich Village, Little Italy, Chinatown, Central Park, Metropolitan Museum of Art (fantastic Tiffanys stuff and Egyptian stuff), Empire State at night, Broadway show (booked over internet), Fifth Avenue, Grand Central Station (which was amazing), Rockefeller Centre (including Top of the Rock - again booked on internet). I wanted to go up the Top of the Rock during the day as it has amazing views over Central Park, so did the Empire State at night for a different perspective. The only things I didn't do which I wish I had (but ran out of time!) were the Flatiron building and Bloomingdales. It all depends on how long you're going for, I was there for 4 nights, so didn't do too bad in the time I had!