You say Zion again, but have you been to the north section of Zion? So many people get stuck on the main valley, the forget or don't even know about the north end.
You say avoid Moab, but how about the section of Canyonlands on the west side of the river? Most folks don't go there because it is so isolated and is a long ways around there. Some place over there is a place called Five Arches.
Then there is Goblin State Park. Very unique Goblins in that area.
All of these places are on my to do list when I retire, but never been too because on the two trips through Utah I hit the popular spots.