I bought Ocarina of Time last week and have to say it really is as good a game as everyone says it is. I never played the original on the N64 so I had to buy this as It's the first 'proper' game I wanted for the 3DS. The game follows the typical Zelda storyline which whilst is repetitive, I had played Twilight Princess on the Wii which was very similar, does provide a great platform for the great game play to be experienced. The main changes to the 3DS version are the much improved graphics which look great in 3D. As you can see from the video the game looks better, however it looks at its best in full motion compared to photos.
If you haven't played the original then this is absolutely a game worth getting, and is by far the best game available for the 3DS.
Also, just a cool little thing to do with the 3DS virtual console. I downloaded Alleyway just to check this out. Holding start and select then pressing on the Game Boy game you want to play brings up the game in it's original resolution with a cool Game Boy border that works in 3D.