The stories in Khazad dum were so good I always enjoyed it despite all the chasms and lava.
On the first play through, Minas Tirith was so bad I actually quit. Many years later, with ten characters through the city, I now consider it easy questing.
My initial reaction to Far Anorian was negative because of the very frustrating terrain maze. These days, having learned the maze, I enjoy questing there.
My initial reaction to Mordor (Gorgoroth Plateau) was very negative because of all the lava, a capture quest, and the very disappointing stories. With four characters through Mordor I now feel much more comfortable questing in the lava areas and my opinion has increased to neutral.
My characters have only made it as far as Northern Mirkwood so I cannot comment on anything beyond that point with one exception. I have ridden through Gundabad and currently intend to let it go gray before I quest there.
Sophie the Enchantress - Creator, Dreamer, Explorer - Happy yet Sad - Seeker of Beauty and Wonder
I wish all of you many successful and happy adventures., brave Ladies and Lords of Middle Earth!