Mike, either coming or going I would recommend that you go through the central part of CO and NM. If you were coming back that way it would go something like this (it has been a few years, so I don't remember all the road #'s). Take 70 west out of Denver, over the top through the Eisenhour tunnels to 91. 91 is just west of Frisco. Take 91 south to Leadville. Take 24 south out of Leadville to Buena Vista. Take 285 south out of Buena to 160 in the san Luis Valley. Take 160 west over Wolf Creek pass, to Pagosa Springs. From Pagosa you can head south on 84 down to Santa Fe and catch I-40 in Albuquerque, or continue west on 160 to the four corners, and drop down to Tuba City AZ and on down to I-40 in Flagstaff. 84 south to Santa Fe is good road and good scenery. 6 hours from Denver to Pagosa, Pagosa to Albuquerque is another 4 hours. From Pagosa to Flagstaff is about 7 hours. If you take 160 west out of Pagosa stop at Mesa Verde, the Anasazi ruins are really neat to see. That is near Cortez.
The views from I-70 to Leadville CO and down to Buena Vista are as pretty as I have ever seen. I grew up In Pagosa Springs and when I drive back to visit my folks I take that route both ways if I can. You are on top of the world for a lot of that drive. I-70 through Utah and western CO is well worth the trip in one direction too.