From the seasons that I've watched Gabon is my favorite location. It was different from the usual beach locations and they were pretty close to some cool elephants. I also really enjoyed Samoa. Call me a sadist but I love it when it rains on them non stop for days and Samoa had the best rain.
I would also probably love the amazon and Palau but I haven't watched those seasons yet.
What are you fave locations? spill bellow.