Tough question XD I think mine are
- The Snow Pit, with Rina. Big spacious map, and quite a bit going on in there. Oh, and I like the escort quest. ;P
- Emberberry Valley. I like peaceful, secluded places, and this small valley with nothing but neutral fruit bats fits that perfectly. Never mind that big guardian roaming around on the top of the hill just next to it, during night. XD
- Schwartzwald Castle, for its size. You go from outside the castle, through the courtyard, past the castle garden and into the keep. And it's all just one map! Plus, it has parts locked off with doors - fancy!
Ooops - those were the maps. If you go by zones, it'd go for Snow Pit, Emberberry Valley, and the Forlorn Manor - nice, quiet, and not really difficult after you got the hang of it. Just fight off the ghosts with your group, we barely have deaths anymore. X3