I read you had the Utah National Parks on the list- excellent choices there. Moab is truly awesome (and there are some cool Utah State Parks nearby), plus Bryce Canyon & Zion.
Consider Glacier NP as well. The Going to the Sun Road is spectacular, and there's tons of nice simple hikes with great views. Black Hills & Mt. Rushmore, Devils Tower can be visited on the way (if you have time).
I see you're in Michigan- we took our kids to the UP twice, and that was cool. Union Bay on Lake Superior near Ontanogon is peaceful.
