I lived in Western Canada and did quite a bit of driving there and in the states. East is Fab, west is fab but the fly over bit, of western ontario, Manitoba , Sasketchewan and eastern Alberta are the same flat endless emptiness. Thats why its called fly over.
The West coast is fab, Oregon, Idaho, Montana, Washington, California, Colorado, Wyoming, Arizona is all amazing, and as said already, the landscape is so stunning that often you are overwhelmed by the scale and beauty. Actual Cities are a disappointment, except Chicago, which is terrific, buildings, centre, Galleries, Museum ( they have an original U boat you can go in).
See the avenue of the giants Redwood Grove.. Monterey , Highway 1 coast road, Pebble Beach golf course, Boeing, Nevada desert. Las Vegas is worth one night, no more, but the desert is amazing. I did Physical Geography at A level and the west of the US has it all, as does British Columbia.
If you want a list of places, pleased to help.