As well as the typical areas near Flagstaff I'm going to suggest making a trip to the West Rim. It costs money because it belongs to the Hualapai. So that means other park passes don't apply.

I think it's worth the view if for no other reason than the lack of guard rails. Of course I may be more thrilled by that than someone with good depth perception but with no barrier to warn you, it's a more natural view.

The west Rim is worth it at least once.