Best of Tucson Tour really is the best.
We found Old Pueblo Tours through our hotel concierge when we accompanied our daughter on her move to attend U. of A. By the second day, she wanted some non-parent time and we wanted to get to know more about Tucson. Terry, our driver/operator, has an amazing amount of knowledge about the U. of A., Tucson and all of its cultural/historical history (he's a grad. student in history at the U. of A.). San Xavier Mission is beautiful; the Desert Museum is one-of-a-kind and of course the beauty of the Sonoran Desert was unbelievable. The only negative part was the heat, but of course, it was August--which we couldn't change since that is when the university begins. Next time, we're going return in January. But, we had a terrific time and highly recommend Old Pueblo Tours.