I would have to say the Lake Bed temple is the hardest one for me because there are so many different options of floors and switches. It gets really confusing going back to the same floor and stuff over and over.
I like the Zora's tunic, Hylian Shield, Kokiri books, and Biggoron sword. Also, I would like to throw out that on Link's Awakening, I get the blue tunic, and prefer to always have the rocs feather and boomerang equipped. :)
For eShop I would recommend a game called "Legends of Exidia". It was actually for DSi Ware, but it's probably the most fun downloadable game I have played. And I have purchased MANY games off of DSi Ware/eShop.
I followed the video walkthrough for Link's Awakening and found it to be extremely thorough. I would love to see video walkthroughs for all the Zelda titles!