I was at the Grand Canyon and Las Vegas earlier this month and had a fantastic time. The drive between them was spectacular; we stopped for about three hours at the Hoover Dam, which is certainly worth seeing, and the tour's well worth the long queue (which in any case moved pretty quickly.
Once at the Grand Canyon, we took a helicopter tour with Papillon, who fly from the airport at Tusayan, and despite a couple of slightly grouchy staff on the ground, the flight was well worth it, the views were breathtaking.
I got up very early to watch the sunrise from Yavapai Point, and though I'm not usually an early riser I'm glad I did.
It seemed to me that there's SO much to see and do in that area that you couldn't fail to be overwhealmed; enjoy!
Update July 2025 (RTA): The photos posted by the author are no longer online.