Times Square is imho only really interesting for the events held there and for the shops around it and in Midtown in general, as a landmark itself it’s nothing special. If you’re looking for landmarks, consider Central Park and the area around it, there’s some fantastic architecture there, as well as numerous museums if that’s your thing.
Yosemite is worthwhile if you’ve got a day or more to spend hiking, if you’re only there for a few hours and sticking to your car, you won’t get to see much at all.
While you’re going to/from White Sands in NM (probably via I-10), consider also visiting Saguaro National Park in AZ (on I-10 near Tuscon) and/or Organ Pipe National Monument (west of Tuscon, bit of a detour).
Have you visited the Delaware Water Gap (which is not in DE, but on the border of NJ and PA)? It might make a good relaxing stop for a few hours after or before the noise of NYC, has some nice short hikes.
If you visit Florida, consider St. Augustine with its Spanish fortress and general historic character and Big Cypress National Preserve (there’s a mostly-gravel loop road off US 41 that’s full of swamp vistas and alligators).