To visit the South Rim of the Grand Canyon the best place to stay with hookups is Trailer Village IN the park. The free shuttle stops at the RV park and you can ride all day long getting on and off. The sites are fairly close to each other but then, you're there to tour not to sit in the campsite.
If you don't need hookups and you have a smaller RV, then Mather campground IN the park is very nice and more spacious sites.
Staying outside the part is a real hassle to drive in each day as parking is limited.
As mentioned above, Bonito national forest campground at the gate to Sunset Crater Nat'l Mon. is a beauty. However, they don't accept reservations so you need to get there by 1pm at least. It does not have a trailer water fill and does not have a dump station. It does have flush toilets but no showers. To me, it's a long drive to visit Grand Canyon but is convenient for things around Flagstaff.
Williams is another town that some folks stay but again, it's a 50-mile stretch of open land to the Canyon. It has multiple RV parks and further away are some forest service campgrounds.
Stay IN the park for the most relaxing experience!
Full-Timed for 16 Years
.... Back in S&B Again
Traveled 8 yr in a 40' 2004 Newmar Dutch Star Motorhome
& 8 yr in a 33' Travel Supreme 5th Wheel