Alby is alright. I don't do anything past normal though. (solo, of course)
Ciar, solo, normal at most is easy also. The only hard spots are Goblin Archers AND Goblins, who both aggro you. :/ Using a pet only messes things up too, so sometimes I screw up if I have a pet out.
Math is long, and I never do it.
I like Rabbie, despite it being long, it's pretty good EXP, so I'm told. I don't seem to get far alone, I always die somehow, but I SHOULD be able to handle it. N>More Concentration.
Barri is a waste of time, always. Barri exists for Ores and nothing else. Only go there for Ores or TNN.
Rundal...never been there.
Coill and Fiodh are both horrendous. I hate them; I can't see anything in the dark, or with the trees and grass, and the monsters are just a pain.
Albey...doing the Gem quests with a friend and other people was a bit fun, but nothing really worth it.
Baol...I'm still on G1.