Scrabania, Rupturefarms, and Soulstorm Brewery in that order.
Scrabania actually looks like a desert, and it makes me happy that it's easy to tell. Paramonia is obviously some type of forest area, but i had to be told what type of environment it was before I actually "saw" the environment. For this reason I'm not too impressed with the look of the area.
Rupturefarms is so diverse and yet not. The different colors of the zulags and a different backdrop to every screen appeals greatly to me, and I wish Necrum Mines or Soulstorm Brewery had done something similar.
Soulstorm Brewery I like because of all the barrels and random pits of death/falls from deadly heights. Not sure why though.