The Legend of Zelda: Ocarina of Time has been hailed by many as the greatest game ever made. And I can see why.
The game has an excellent storyline. It makes you feel like you actually are Link and that it actually is your duty to save Hyrule from Ganondorf. It is not too cheesy of a storyline, and it can keep you interested. You will not be able to put it down because you will always want to find out what happens next.
Aside from all that, the Legend of Zelda: Ocarina of Time has the best graphics of any Zelda game made yet. Granted, Zelda GCN probably will take OOT's place in that category, but it will never take its place on the effect that it had on the gaming industry.
Ocarina of Time was a revolutionary video game. It changed the way people think about gaming, and allowed Nintendo to set higher standards for future games (They haven't really paid much attention to the standards what with "Cel"da coming out).
Yes, OOT was a truly great game, and any gamer who hasn't played it is missing out.