FF6 was teh first game I played that truley amazed me. The whole time I was playing it I was in awe, the hero's, the villian (Kefka is in my opinion the best villian ever in a video game), the world, the story, the magic system, and of course the outstanding music, they were all ace.
I don't think I'll ever forget the boss battle, how intense it was, I truley felt like it was real (I was like 12, mind you, but still).
FF6 was the complete package, nothing like it had ever been done before, it was the most ahead of it's time RPG that has ever been released.
FF7 is a great game, but I think it gets more credit then it deserves.