American Southwest

I am planning to head to the American Southwest in the Autumn; flying in and out of Las Vegas, staying there 4/5 days followed by a few days hiking in the Grand Canyon.

On top of this I have another 3/4 days to spend travelling around the area; I am probably limited to Northern Arizona/Southern Utah or maybe Western New Mexico & Southwest Colorado. I have been doing my research and I am trying to pick out some good places to visit but there is a lot of choice e.g. Monument Valley, Bryce Canyon National Park, Arches National Park to name a few.

I want to pick out 2 or 3 locations and get the most out of those rather than spending short amounts of time in several places. Does anybody have any recommendations or must see places that you could suggest?

Must see - Bryce Canyon, Zion National Park and Monument Valley - Don't go to ths Southwest if you aren't gonna get to there IMO - They are out of this world ! Fantastic. Enjoy !

Have to agree with Havealaugh.
Drove from Vegas to Salt Lake last year and both Zion & Bryce are well worth seeing. Both have nice hikes through them as well with some stunning scenery.