I haven't been everywhere by any means, but this place is hands down my favorite. Colorado's Great Sand Dunes National Park features mountains of sand oddly plunked in the middle of a massive flat valley/basin. They are just so inexplicably...there.
Typically I like to camp overnight in the dunes themselves. Its quite an experience. Unfortunately on this trip I was chased out by a storm. Having been blown away in a tent there before, I had no intention of taking on mother nature. Oh well. got a fun hike and some cool pics out of it.