Grand Canyon, Arizona
If you ever get a chance to visit, take it. Inconceivable (to me at least) in this day and age where travel around the planet is accessible to so many and so economically reasonable that anyone would live their four score and ten without finding a way to get here for at least a day. If you can make it to Las Vegas, you can get here. (Literally, they’re not that far apart.)
This is from the South Rim which is the most easily accessible, has the most restaurants, camping/lodging facilities, tourist amenities, parking, etc. The North Rim is better IMNSHO, but requires a bunch of hours more driving each way and is considerably more limited in the facilities available. (Psst – it’s worth it!)
Either way, GO!