These are the national parks I have visited since my childhood Grand Canyon, petriefied forest, hot springs,death valley,yosemite,redwoods,joshua tree seqouia mesa verde, rocky mountain,mesa verde,everglades, biscayne,acadia,glacier,yellowstone,grand teton,calsbad caverns,great smokey mountains,crater lake,badlands,arches bryce zion canyonlands,capital reef,shenandoah,mount ranier mammoth cave.
My 2 favorites are Zion and Yellowstone