It’s just a very well made game. Everything about it is good. The story is good. The temples in the adult world are very well made. The characters are good. Even the soundtrack is good. It’s more like a film than a game.
Probably my favourite game of ever, although I’m not really a massive gamer. I don’t know what all the ‘best’ games are considered to be (or the indie equivalent). I only had a GameCube (my copy of OoT came free as a bonus disc with The Wind Waker), never had a Playstation/Xbox console or even a N64.