>>923446Flagstaff is a nice mountain-y town. I've been up there a few times but I couldn't tell you everything about it apart from the fact that it's pretty up there.
The meteor crater outside of Winslow is pretty neat, but it is on private property so you may have to pay to get a decent view/tour.
The Grand Canyon is one of those things you gotta see. I've been and it's just one of those great sights to see in the western U.S. I would strongly urge you to check it out. Pic related: the initial cliff on the south rim