I got some time last week to churn out a few of them, so here are the first three.
I figured it was only natural to begin with the three transformation masks. These are the three main transformation masks acquired throughout the game (there's one more final mask, but it's at the end of the game and optional): the Deku mask, Goron mask and Zora mask. Link acquires these in various ways, but the end game is that you get to transform into these races at will. It's amazing fun. And I guess useful, too, if you can stop swimming around as a Zora and shouting "Look, ma! I can leap like a dolphin!" for long enough to actually do some quests and save the world.
I've moved! You'll now find the rest of this post here at the brand new Cakecrumbs