Which, if any, national parks have you visited?

My wife and I are having our first visit to Yellowstone in two weeks (we very recently moved out west), so I started thinking about the NPS. If you're not in the USA and have never been to one of our parks, you can describe whatever's equivalent (as far as things can be across nations) for your life. If you've never been to a single national park, which one(s) would you like to see before you die?