OK, my National Parks list from mostly the last 10 years: Grand Canyon (North & South Rims), Yellowstone, Zion, Bryce, Grand Teton, Arches, Canyonlands, Denali, Rocky Mountain, Black Canyon of the Gunnison, Mesa Verde, Dinosaur, Petrified Forest, Mammoth Caves, Gettysburg, Smoky Mountain, Colonial Williamsburg, Yosemite, Jewel, and maybe a couple of others which escape me at the moment (not counting National Monuments and Memorials from coast to coast).
We have a lifetime National Park Service Pass and have completely filled our first National Park Passport and gotten a good start on the second.