Which MM non-transforming mask is your fave?

I really liked getting the smaller masks in Zelda: Majora's Mask. I am personally the type that likes side-quests, and as a story-writer myself, enjoy getting to know all the more minor characters in the story. Especially that Anju-Kafei run which, while annoying in some respects, certainly has its reward. So, what about you? Do you like the masks with sentimental value, useful value, or do you just really like blowing stuff up with your face?