Celes

Also known as Seris depending on the translation.

I always thought Celes was awesome. I always liked the old "Ex-villain" characters, but she was also the best at EVERYTHING! She had perfect stats and could use magic, AND on top of all that, could use Runic (absorbs any magic used by enemies and will recover MP with it).

There is also a lot of arguing over what Celes actually looks like. The original character design was like this: [link] but the game sprites were based off this: [link]
so they are both technically official. FF does that on occasion... Ignore entirely the character designs they paid for XD