My boyfriend and I felt we "discovered america" in New Mexico during our two week roadtrip of the west. We basically did what you described. In the morning we took out the map and decided where we wanted to go, and changed routes whenever something seemed more exciting. No doubt though, try the JEMEZ TRAIL in northwest new mexico. Its north of Albuquerque, i don't remember exactly what highways we took, but look it up, you will absolutely NOT be disappointed. Oh, and go to Chaco Cultural Center-basically, pueblo ruins in the middle of Nowhere. It was spiritual and absolutely breathtaking. Anyways, thats my suggestion. Its how we found america.