One of the best JRPGs ever made by men
Final Fantasy 6 has the most number of playable characters in the series, with each one having a meaningful backstory, plus, the game doesn't really have a main protagonist. That was something that the developers wanted, making most of the characters equal to the importance of the party and having an emotional attachment with the player, and they succeeded.
The game also has a diverse soundtrack that is considered a masterpiece, with a sensational contribution for a sense of atmosphere, making a powerful score.
They managed to put together all the great things from the past games in the series, and make a well-crafted game to finish the 2D era, even taking up a notch on the storytelling and the visuals as high as possible for a SNES game.
The game has one of the best opening sequences of all time in gaming. The story has such a great pace, and take some risks that really pay off. Hironobu Sakaguchi selected a few of his best colleges to help him write the characters, as you can tell by their diverse and in dept plots.
Another thing to point out is that FF6 has the best villain in the series, not being a god or some sort of crazy idea, unlike past games in the series. He is just like Joker from Batman if you gave him a cyberpunk universe.
The game has amazing backgrounds, considering that the game is from 1994, it has to be one of the best looking games of all time. And the really well-designed gameplay, with the variation from the Magicites as well as each character having his personal skills and stats.