Classical game, hated by ones, loved by the others. One thing is sure: you shouldn't miss this one!
The story presented in this one is definitely one of the most interesting and touching in a FF game. You'll love the characters and have a lot of fun as they will grow up just before your eyes. Not trying to spoil anything for you I can just tell you that the ending is worth watching.
I'm not sure what you'll think of the battle system, it's very controversial. There are some who say it's confusing and pretty much pointless, the others say it gives you the opportunity to make your characters as strong as you want. I can only say that it's interesting and fun! For a game that was released more than 6 years ago, it still has pretty good graphics. Magical effects and summons (GFs technically) look pretty well and the FMVs are still gorgeous. What's the best in this game is the soundtrack. Nobuo Uematsu has done wonderful job in both FFVII and VIII - this one has the 'Eyes on me' hit though. I'm sure you'll love the final battles music and you'll keep humming some of the more peaceful ones.
There isn't anything I can say about this one that wasn't said at some point before. This game is the classic already - you have to play it to see why!