Favorite would be the Archeologists Camp. Trackless desert behind, mystery of time immemorial in front. That's always where I feel like I'm entering the part of the map the cartographer wrote "Here Be Dragons" on. Even though there are dragons everywhere.
Least favorite would be any town in the swamp except maybe Lizurath. Especially when it's storming. Just an eye-strain nightmare for me. I always find myself screaming at the screen "No! Knee-high fences! My one true weakness!"