Not that Israel is "done", but now that I've been there (albeit for a short trip) it doesn't really fit into this list anymore.
I also removed the Ice Cliffs of Austfonna, Patagonia, and New Zealand. I still very much want to go there, but they're not top 10 at the moment.
Updated, in no particular order,
1 - South Georgia
2 - Great Barrier Reef
3 - Kyrgyzstan
4 - Deadvlei/Skeleton Coast, Namibia
5 - Kamchatka Peninsula
6 - Erta Ale, Ethiopia
7 - Socotra, Yemen
8 - Komodo National Park
9 - Gabon
10 - Palau
Other things high up on the to do list are Guatemalan volcanos, Siberia in the winter, Cabo Verde, Galapagos, Greenland, Mongolia, Hokkaido, Madagascar, Angel Falls, and a good nap.
Alaska Done!
Hawaii Done!
Iceland Done!
Cuba Done!
Norway Done!
Antarctica Done!
Kenya/Tanzania/Botswana Safari Done!
Lençóis Maranhenses Done!
Israel "Done"!