Which new zone in Mists of Pandaria has been your favorite, can be for whatever reason, and then post your least favorite zone stating the main reason.
My favorite is Jade Forest with Kun-Lai and Valley of the Four Winds following right behind it. I found those zones the most refreshing, with the most engaging quest lines (especially Jade), I also loved the zone designs for all three, they were gorgeous. (I don't know about Karasaung Wilds I haven't done that one yet).
My least favorite by far has been Dread Wastes, it was a pain to get on the wall for me to start the quest lines, and from the quests I did it was mostly on the old un-engaging format, and the zone seemed ugly and un-inspired compared to some of the other zones. Townlong was close though, but mostly because I found it just plain bland to be in.