Advice on NYC to Phoenix

I'm travling from NYC to Phoenix. So far we've planned the following places to stop.

Col. OH
Chicago (kind of off track but have to visit some friends)
St. Louis
OK City
Santa Fe
Flagstaff/Sedona
and then to Phoenix

Any suggestions on cool things to see and keep an eye out for on the way? I used my AAA to get the best route to take and this is what I got.

Any info would be a great help!

St. Louis - see the GATEWAY ARCH

Oklahoma City - see the bombing memorial

If you have time:

From Oklahoma City, you could jog North & go to Durango CO & MESA VERDE National Park, then come into Arizona via MONUMENT VALLEY & the GRAND CANYON, then down through Flagstaff & Sedona to Phoenix.

OR From Oklahoma City, you could jog South & see Fort Worth / Dallas (historic stockyard, see a rodeo!), CARLSBAD CAVERNS National Park New Mexico, and across to Phoenix.

Adding to Syv's list, you could also see Dealey Plaza and the 6th Floor Museum in Dallas, and Lincoln County, NM, site of the Lincoln County War. You can still see the bullet holes in the courthouse walls from when Billy Bonney shot the sheriff! And White Sands National Monument!