The United States of America boasts 397 national parks, which covers about 84,000,000 acres of protected land. You could spend a lifetime trying to visit them all. I have only seen two so far (Yellowstone in Wyoming and Badlands in South Dakota), both of which were spectacular.
After seeing this video by Sheldon Neill and Colin Delehanty, Yosemite might have to be next…
Yosemite HD from Project Yosemite on Vimeo.