Ah, there's a really nice loop going Vegas > Grand Canyon South Rim > Page (Antelope Canyon) > Bryce Canyon National Park > Zion National Park > Vegas. Quite a bit of driving, but very beautiful places. Can extend the loop to even include Arches National Park and Canyonlands National Park, but that's even more driving. Although, it's near winter time, so I'm not sure how are the road conditions at the higher elevation places (Grand Canyon, Bryce, Zion).

The national parks in Utah are so beautiful, definitely check out as many as your time and energy allows. Wish you a fun, enjoyable, and safe trip!