I was in NYC w/family for a few days in spring break.
My two bits: Statue of Liberty...good but takes the whole day. Security Checks were Murder.
Empire State: didn't make it...lines too long..2hrs Plus. More security checks.
Rockefeller Center has an observation tower. Try that.
Sony Building 55th/Madison tour and or NBC studios tour...alternatives for a
Theater: if you can get to TKTS (46th and broadway)...get some 50% off tickets and see a show...THAT day. Wicked is sold out..but there are plenty of other shows (We saw three...enjoyed all).