re: What is so good about Majora's Mask?

The sense of hopelessness and despair, along with the stress of repeatedly-impending doom, are part of what make it great. It's a different kind of game, but still the dungeon puzzle solver type of Zelda experience you get in the other games.

Think of it as cyclical instead of linear, as an Eastern philosophical experience instead of the traditional Western temporality. Your actions have karmic implications when you're "reborn" every three days. It's the wheel of time, not the river of time.

That, and the ending is still somewhat hopeless and depressing. I'd like to play another story in Termina instead of always in Hyrule.