re: Route Suggestions/Hotspots for Traveling America By Car

Seriously though, hit these national parks, probably in somewhat this order, skipping Texas:

Carlsbad Caverns
Painted Desert / Petrified Forest
Stop in Gallup, NM at Jerry's Cafe for the BEST New Mexican food on the planet
Antelope Canyon (not a NP, but still awesome. Do one of the native american tours.
Grand Canyon (North Rim if you are incorporating some of these others, and depending on time of year. South Rim if you bypass some of these, or just add more time onto the trip)
Bryce Canyon
Zion

After this, it depends on where on the west coast you are wanting to end up... further north, or east of Zion.

I freaking love road trips. We've done all of these.