Majora's Mask is undoubtedly the deepest, most mature and complex Zelda game to date, and my personal favourite. All of them have their plus points, from the sheer freedom of the original, the sense of discovery in Link's Awakening, the beautiful multiple states of the Oracles games, the unique controls of Phantom Hourglass and the sheer sense of characterisation of Wind Waker. But for me, it is the sense of inevitability, impending destiny, the tragedy of death and love unrequited, of doomed relationships and forgotten heroes that Majora's Mask has, and no other Zelda has since equalled.
SKRAT! HEIT! SEET! YAHHH!