If you go to Rockefeller Center, look at their website
© Rockefeller Center 2003-2006 for a listing of the restaraunts in the basement and the tours available. Buy before you go, and you get a specified time. Not bad and not too expensive. We did the NBC tour, and got to see the Saturday Night Live set and my kids got to do the weather with the "invisibility cloak".
We've done Empire State Building, and again, but your tickets ahead of time. No waiting in line to buy them, just waiting in line to go through.
Research, plan and keep notes. I bought a laminated map of NYC that I kept in my purse in case we weren't sure where we were supposed to go next, and it was helpful.
The South Street Seaport is something I did not know about. I had no idea it was there, so that' something we plan on doing next time.
You'll have to do a TR and let us know about the Navy Lodge in Staten Island. My Dsis will want to do that too!