Hell yeah! These are some amazing places and I've only missed out on going to Machu Picchu on your list! The Great Barrier Reef is flipping awesome and some of the corals alone will blow your mind. I saw giant clams when I went snorkeling there in 2015 and it's sad to learn of the bleak future of the corals with such a vast amount of it on the brink...
Yellowstone is a beautiful place as well, have visited a few times and it's incredible. We've seen herds of hundreds of bison cross our path on the main road in to the park, we saw Brown Bears as well from a distance and the grand prismatic spring has some amazing colours!
Good luck in the contest!
Nice! Great to hear you have been to a couple of these awesome places :)