Some input on roads from Phoenix to Denver

[wakeupngo]

Hi all!
I'm from NYC.. looking for some great open roads in the Southwest. I decided kinda spontaneously to fly out to Phoenix (actually.. tomorrow night). I'd be driving up to Denver. I'm doing this trip from Monday-Friday. Obviously, I will need the abbreviated version of all these places due to time constraints. Just looking for some great routes, beautiful sunsets, and amazing views in an area of the world I have yet to explore.
Some sidenotes. I'm a female in my early 20's and doing this independently... so, while freedom and the open road is something I always crave, I'm looking for safety, as well. I'm not sure I want 100-mile roads alone without gas stops, motels in the middle of nowhere (basically, anything that reminds me of the movie, "Psycho"), or anything of that general nature. However, at this point.. I'm trying to keep my mind open to anything... except knife wielding motel owners. Any help would be appreciated! Thanks!

OH.. another quick question is what car I should rent while down there.. thanks!

Francesca