When I tell people how many National Parks I have visited, they usually ask, "Which one is your favorite?" This is a fair question, but it is not simple to answer for two reasons. First, there are three parks that are essentially tied for first. Second, there are two other parks that may actually be my favorite, but not for the usual reasons.
If forced to name my single favorite park, it would be Yellowstone National Park in Wyoming (with a bit of overlap into Montana and Idaho). Yellowstone was my first big famous national park (my third overall), and it has a larger variety of things to see than any other park. Yellowstone has geysers, mudpots, hot springs, lakes, mountains, canyons, rivers, waterfalls, trees, animals, and birds all in one place. Moreover, the thermal features, especially the geysers, are something one does not see in everyday life. They are awesome.
My second contender for favorite park, Olympic National Park in Washington, also has a great variety, and it is beautiful. It has three distinct environments: Rain forest, ocean beach, and mountain. Beach and mountain environments are not unique, but rarely are they seen in such close proximity. The temperate rain forest is something not seen in many other places. It is like an Eastern forest on steroids. Everything is greener and the green is everywhere. Olympic is where I first saw tides with my own eyes. I am not from near the ocean, so tides were always a rather theoretical thing for me. Seeing the same beach at low and high tide made me a believer.
Glacier National Park in Montana is known for beautiful mountain scenery. This would include the mountains themselves as well as lakes, rivers, forests, glaciers, and waterfalls. Going-to-the-Sun Road is often called the most beautiful drive in America. I do not argue with these descriptions, and Glacier is my third contender for favorite National Park. It does not have the variety of Yellowstone or Olympic, but for sheer beauty and majesty, it has no equal. I am also somewhat partial to this park because I did extensive day hiking there. The Grinnell Glacier trail is probably the finest hike I have ever taken. As time goes by, Glacier rises in my mind, and some day I may very well count that as my very favorite.
So, we have a virtual tie between Yellowstone , Olympic, and Glacier as my favorite National Park, but what about the other two that I mentioned? Saguaro National Park in Arizona is my favorite in a different sense. I have been there six times, more than any other National Park, and I know the Tucson Mountain District almost like the back of my hand. I love the saguaros, and I know this park so well that it seems like my own little park. I have a connection to it that I do not have with any other National Park. In this sense, it is my favorite.
I have this same sense of connection to Pictured Rocks National Lakeshore in Michigan, with the bonus that the park is quite beautiful. I have been there even more than Saguaro and know it even better, but it is not a National Park proper. If the question asks which is my favorite unit in the National Park System, then I can answer "Pictured Rocks National Lakeshore." PRNL has trees, rivers, lakes, secluded beaches, and waterfalls. Above all, however, it has Lake Superior, the greatest of the Great Lakes. The cliffs tower above the lake and the views are magnificent. The Chapel/Grand Portal Loop, which partially follows the top of the cliffs, is my favorite hike. The view of the cliffs from the commercial tour boat is also quite striking. Really, the only reason PRNL is not my favorite National Park is because it does not qualify in that category. If we ever have Pictured Rocks National Park, it will be my favorite.