My favorite state / DLC is Utah as its basically a mixture of Colorado, Nevada, and Arizona itself. But I just got the Colorado DLC and it has been amazing so far.
My favorite state in the simulator right now is Utah. I always love driving through Moab and Monument Valley. I would love to see Texas added in the future though.
I honestly enjoy driving from Moab to Flagstaff. Or Salt Lake City to Flagstaff to see all of Moab. I enjoy driving through Monument valley and driving to the Hole in the Rock area near Moab. I have been to this Area irl which influences my love for it but I still enjoy this route a ton.