The very first one. Have you ever wondered why it was called that in the first place?
Uhh...
*points behind Sarge at a black hole, and runs away*
<Acacia Sgt has been disconnected.>
(Our name for that is Dividing By Zero.)
Not sure what you meant by that. But anyway:
It was called that because at the time, Hironobu Sakaguchi, the director, announced he was doing one last game. He decided his FINAL game would be a FANTASY role-playing game. If it did not sell, he would quit making video games.
But as you can see, it was a succes. They decided to make a 'sequel', so to speak, but decided to keep the name, adding just the 'II'. And the rest is history. Got it?