I very rarely or never play:
Passage through Mirkwood - Too easy
Journey Down the Anduin - Very good quest but bored to death of it
Conflict at the Carrok - This one is like putting the same puzzle together again every time you play it
Flight from Moria - I really like this quest.....for some reason I just haven't played it for a while
Road to Rivendell - So boring, however the enemies in this quest are great I think.
Watcher in the Water - You do not know how much I hate the tentacles.....
Shadow and Flame - ehhh
The siege of cair andros - I built a deck that beat this quest 15 times in a row and two times I had a mumak on the first turn. It was easier than passage through mirkwood. Haven't played it since.
Blood of Gondor - ehhh I just didn't like it.
I didn't really like any of the Voice of Isengard quests that much. I do not play those very often at all.
All the Saga quests I rarely play also.
Now at that time the Chieftain of the Ringwraiths dwelt in Minas Morgul with six companions, while the second to the Chief, Khamul the Shadow of the East, abode in Dol Guldur as Sauron's Lieutenant, with one other as his messenger." - Unfinished Tales