Playing through Majora's mask right now.
I can see why so many people like it so much. It's really fun ._.That's awesome dude!
The biggest thing about MM is that it's primarily side-quests, with only 4 temples, making the given Heart count a measly 7. Between the 13 hearts worth of pieces as well as all the masks, bottles, and other items (particularly the stray fairies) it can be a real challenge.