Planning on visiting on Thanksgiving Day. Should arrive at the hotel around 2 pm, and then hit the ground.

This will be my first visit to NYC, thanks.

You won't want to be anywhere NEAR the Empire State Building on Thanksgiving. The Macy's parade is just a block away, so the cowds will be overwhelming just after the parade. Most of the sites will be closed on Thanksgiving, so you will mostly be window shopping. I'll bet the Christmas Fairs will be open, at least some of them and the Skating rinks will be open, and maybe some stores in Times Square, but most of the sites will be open on Friday and of course that is the BUSIEST shopping day of the year.

Have a great time while you are here.

Do not do this. The lines for the ESB is usually a couple of hours long. On Thanksgiving Day - with the hundreds of thousands of people from the parade, it will probably be worse.

Much better to ascend Top of the Rock - and do it another day - when the wait shoud be no more than 5 minutes or so.

Also be aware that most restaurants are closed on Thanksgiving - so you definitely should have advance reservations.

Thanks for the warnings.

This is a very short trip, I'll be arriving on Thursday and leaving on Sunday.

Which day would be best for the Top of the Rock?

Monday.

Seriously though, the best day would be whatever day you can get tickets. The area will be packed with people Fri/Sat/Sun and I would expect all 3 days to be equally jammed.

If you do go to any museums then go early in the day, again to avoid crowds in confined areas.

If you have an option I'd pick a time around sunset. You can check times at sunrisesunset.com

You need to let the weather help you decide. If it's rainy or very cloudy you won;t see much. If you get a decent day head up around sunset - so you can see the city both in daylight (although Central park won;t look like much in Nov) and with all of the lights on,