Okay, here goes...
- FF I: Not very heavy on the story, and there's a few annoyances that they fixed in later games. You can choose what characters to play from the start. It worth the 5/600 Wii Points on VC, if you have a Wii.
- FF II/IV: More focused on story, you play as a knight. I find the Engrish in this game a little bothersome, but maybe they fixed that in the DS version. Again, if you got a Wii, this is 8/900 points on VC.
- FF III/VI: Many consider this to be the best in the series, and I'm not gonna dispute them. Kefka is probably one of the best villains in video games. 8/900 points on VC.
- FF VII: This is my personal favorite, and it's due for a new release on PC (probably this year). I like the characters, I like the world. VII is a change in the series as they went from 2D to 3D, they also changed a lot of the aestetic of the series.
- FF VIII: I don't like it. None of the characters are appealing to me, the story is riddled with plot holes and drawing magic sucks. It looks a lot better than VII, but that's about the only good thing I have to say about it.
- FF IX: Haven't played it. Many people say good things and it seems to be a call back to the games before VII.
- FF X: I don't know about X. I don't like most of the characters and the story makes sense only as long as you don't question things. Character progression also makes character individuality non-existent. It has a good combat system though, and if you find it in the bargain bin, it's not a bad game.
- FF XII: I like this more than X, mostly because the story is better, as are the characters in your party. The only problem with this game is that your character's involvement in the plot is pretty superficial.
- FF XIII: I bought it and then my Xbox broke, so I've probably haven't played more than 3 hours of it. From what I hear, this game is 75% tutorial and that's certainly true from the three hours I've played.
I know a lot of people disagree with me on VIII and X (I like X, but I don't think it's as good as other games in the series).