As for NYC, there is PLENTY to do but without a more specific idea of what you want to do the list is endless. I will list my favorites:
RESTAURANTS
Dylan's Steakhouse - Tribeca
Amazing steak house with a different atmosphere. It is a bit dark inside which sets the mood of the restaurant but the food is AMAZING. Also not that expensive. Runs about $50 a person for a nice size meal. Appitizer, meal, & dessert runs about $75 a person. Drinks run it up from there.
Jekell & Hyde Restaurant - Central Park
If you want entertainment, this is a good place to go. Live entertainment and actors run around the restaurant while you eat and the whole restaurant atmosphere is like the original Jekell & Hyde movie. Also love of puppets, a wall pharo that talks, etc. Although it sounds like it might be something for people that are younger, this is great for all ages.
Hard Rock Cafe - Times Square
If this is your thing, then I would recommend attending. Tends to be a LONG wait since it is now in Times Square.
Dealerships
Manhattan Motorcars - 17th Street
This is a LARGE dealership with every car that you can imagine. Authorized dealer for Porsche, Lamborghini, Saleen, Spyker, Bentley, BMW, & Rolls Royce
Ferrari/Maserati Showroom - Park Ave Midtown
Has usually 3 or 4 cars on display. Not a dealership but nice to see how they set it up.
Bentley/Lamborghini Long Island - Jericho, Long Island
(30 Minutes from NYC)
If you want to see a collection of cars, this is the place that you have to go! Manhattan Motorcars is huge with lots of variety but if you want to get out of the city and see what a dealership can do with land and inventory, you must go here. On any given day, you can find at least 200 EXOTIC cars at the facility. Autorized for Lambo and Bentley but have a whole second showroom for all other exotics. Now they have two Porsche Carrera GTs, A Ferrari F40, Noble N400, 5x Ford GTs and that is just a few!!!
SIGHTS
There are plently that you should see but here are a few that come to mind:
Central Park
Times Square
The Plaza Hotel
Rockefeller Center
Fifth Ave & Park Ave (Can Make You Go Poor Quickly)
If you want more information on any of these destinations or addresses, please do not hesitate to ask. I know there is A LOT more to do but this is what I can think of at the moment. Adrian, feel free to chime in.