Already going on Arctic Sweden exped so voted for Namibia being my second choice.
As all options probably reflect the major exped types well, Jungle, Arctic and Desert, in reality, I would jump at the opportunity for all of the exped's.
Of all the folks you mix and talk with in daily life, how many have seen and experienced first hand, the Arctic, Desert or Jungle....Not many (Unless you are forces)
Purely my own opinion, life is not a dress rehearsal, if each exped becomes reality, my intent is to do all I can to be there