I used to drive from Denver to Flagstaff back to Denver at least 3 times a year. The main route I would take was through Albuquerque, since I had family there. During the summer months I would take I-70, make my way to Moab, and through the Navajo Rez. It was a nice drive, although it did get kind of HOT once I past Grand Junction. My favorite route was to go through the 4 corners, Mesa Verde & Durango. I only did that a couple of times since it required more stops to take in all the great scenery. For me anyway.