Ocarina of Time (3DS).
This is, oddly enough, the Zelda game I've played the least. I've never finished it but now that I have the 3DS version I'm really digging it. The hype surrounding this particular entry in the series put me off for years (I love A Link to the Past and was annoyed when people said that Ocarina was better. 'How dare they!?' and so on. But now I can totally see why someone would hold this game as the best Zelda ever, especially back in 1998.
I still prefer ALttP cause it was my childhood, but I had I played Ocarina when it was new I might have loved it even more. But since I already played through the likes of Twilight Princess and Wind Waker, this obviously isn't as revolutionary anymore. Still, it's a very classy game.