Having visited 52 of the 62 US National Parks, (I lack the 8 in Alaska, and American Somoa) I must say that each (most) are unique in their own way. I have 8 children and sometimes they try to ask their mother which is the favorite. That said Olympic has crazy geographical diversity and Yosemite might top my list if it was so crowded. Glacier is a place I want to spend more time.