The hardest dungeon for me is The Water Temple from Ocarina of Time. I can not fathom the hatred I have for this dungeon. Along with its seemingly basic but trecherous room system, I eventually got to this one part where I found out that you needed a KEY to enter and I was completely out of keys. So, long story short, I was stuck for not a day, not a week, not a month, but 2 YEARS!!!!!!! Thats INSANE and i had to resort to youtube for where the lost key was because all text walkthruoghs were too complicated for me to understand and well, it was simply aggrivating to have to do that. And now when I hear the Seranade of Water, chills go up my spine