XII - Going to restart playing. The story was so freaking boring in the beginning I didn't pay much attention, and I guess I'm a little lost.
I wouldn't bother if I were you because that boringness doesn't change. People get together and speak vaguely about people, places, and things that you don't know (and they don't explain what/who they are), you are told to go somewhere, you get there and wonder around killing monsters, an anti-climactic boss character fight, time jump (they never say how much time elapses), more vague talking, you are asked to go to a new location, more wondering around, over and over and over again. I've had the game for what...2 years now and I haven't beaten it because it's not fun and I have no idea what the heck is going on. Just a bunch of talk of "The Empire" and rocks.
As for the other games...
VII - I first played this when I was 8. After Super Mario Brothers, Donkey Kong Country, and a mountain of racing games I was awed by this so called "RPG". Loved the battle/materia system, plot (though hitting "x" for 30 minutes of story development was a bit irritating), and characters. Cloud, Sephiroth, and Chocobo breeding are permanent memes in my family.
VIII - I liked it but the Junction system drove me nuts, if I can attach 99 Ultimas to my weapon and hit 9999 why bother with leveling and crafting weapons? I also thought the side quests were more fun than the actual game, (except for the card game that sucked once they stared changing the rules). The whole "orphanage" thing was the worse excuse for character development I've encountered.
X - This is my second favorite next to VII., the plot twists and ending were pretty epic. The ability to switch out character in mid-fight was cool (but time consuming because I did it constantly), had a love-hate relationship with the Sphere Grid.
XII - As I said before this game plot wise is a complete mess. It's like they took parts of old Final Fantasies (Mount Gagazet FFX, ShinRa Building the day after Sephiroth releases Jenova FFVII, Empire vs. "the Resistance" FFVI, etc.) and made a game out of it. The only good thing about it were the graphics, the Gambits, make an awesome gambit and the game plays itself. As for something that don't matter but I still disliked -the voice acting. It was awful, everyone had some weird accent and 90% of the males sounded almost exactly alike.