The swamp area that you had to take from Bastok to get to Jeuno. I forget its name but it was cool.
(These are all going to be spelled wrong...)
I liked Zi'Tah, the Promys, the Citadel/Necropolis/Obaulette and Carpenter's Landing. There was something about areas like Carpenter's Landing that were small and somewhat insignificant, but carried it's own atmosphere.
Taking the raft, without teleporting and fast travel, let you soak in the world some more.
I hope that there are little areas like this that make you slow down a bit and appreciate the world.
I don't want to derail too much, but what makes a good zone is as much as the zone itself, as it is the destination to get there.