A true classic loaded with quality and nostalgia
OoT puts you in control of a young boy who lives in a forest village and is chosen by the Deku Tree to, well, save the world. Eventually he visits Hyrule and acquires the Ocarina of Time, which he must use to visit the future and defeat his enemy, Ganon, there. The story is really cool and time traveling always calls for neat plots.
OoT is pure nostalgia at every corner, and that feel rarely leaves you no matter how much you play. Whether you're in the Deku Tree, the Forest Temple, or just running across Hyrule Field, you always have that cool feeling.
Zelda's move to 3-D was definitely for the better. I love the puzzles even though I get stuck on almost every one (I'm pretty bad at most Zelda games), and the dungeons are all really cool. The puzzles can be annoying sometimes, but that's just because the people who made the game were so ingenious as to think of such great puzzles.
The graphics are great for the time and the controls work very well, and the sound is also excellent. It was the N64's defining game, even winning over Super Mario 64 in the minds of most fans because of this technical aspect as well as just how great the game is.
People make this game out to be the best game ever, 10/10 ratings, all that. Me, I just don't think it's perfect. I occasionally get frustrated with things that should have worked better and the day/night feature is cool but can be a little on the annoying side (I want into Castle Town... but the drawbridge is closed! And there's an army of skeletal monsters out to kill me!).
Really though, the minor complaints one could think up can't make this classic a bad game, it just has too much nostalgia and too many great puzzles to make it so.