We have been lucky enough to visit the Utah parks, and my favorite of them all is Zion. Arches, Bryce, Canyonlands, and Capitol Reef are all excellent, but Zion is spectacular (I place it in my "Top Four" of national parks, along with Yellowstone, Grand Canyon, and Glacier). For hiking, my favorites are Zion and Arches; the Double "O" Arch hike at Arches is one of the best I've ever taken, along with the Hidden Canyon hike at Zion. Be sure and take water with you when you hike in Utah!