Def do Vegas - Grand Canyon / Hoover Dam.

Hotels have agents they deal through that let you do deals from memory we paid about $120 pp for 3 hr flight over canyon and hoover dam, included transport to and from hotel.

Or rent a car and drive the 45 mins to hoover. Then take the tour walking through tunnels with water pouring down the sides... lol

Def do the rides on top stratosphere tower at the end of the vegas strip.