Furthest would be Australia and New Zealand. Australia and New Zealand were great places, friendly people and a lot like the US 30 years ago. Only saw Auckland and some of the surrounding area. In Australia we were in Sydney. Great metropolitan city. They Sydney Opera House is acoustically unbelievable. The best part was a few days in the Blue Mountains outside Sydney. The eucalyptus trees give it a blue hue. A large canyon like the Grand Canyon, it is a World Heritage Area. The picture is of the Three Sisters at Sunset (By JJ Harrison (email@example.com) (Own work) [CC-BY-SA-3.0
(http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons).
Most different would be rural Mexico (you can check out my Hub on this) and Saudi Arabia (Gulf War). I don't spend a lot of time in the US desert southwest but in some ways Saudi was similar. What made it different was how they treat women and suppress other religions.
Distant and unusual places I would like to go include Uruguay, Peru, Galapagos Islands, Easter Island, Canary Islands, and Tanzania.