Well, here's a summary of the FF games:
FFI: The least linear of the FF's. Basically four "light warriors" have to kill Garland. Then they fight pirates and elementals only to find that Garland's gone back 1000 years to become Chaos and they have to break the loop.
FFII: Basic rebellion. You have to kill an emperor and then kill him again in hell. (But where's he going to go this time, Detroit?)
FFIII: Hope you have an emulator.
FFIV: You start out as a bad guy, then become a good guy, your friend then becomes a bad guy, a good guy, a bad guy, and again a good guy. Eventually you go underground and to the moon to recover the crystals.
FFV: Probably the dumbest name, ExDeath. Either way, you reunite the world and then have to go into a singularity to fight ExDeath.
FFVI: Soap opera. The first half deals with rebelling against the empire, with a girl who can't remember anything as the main character. The second half is less linear, and focuses on tying up loose ends and ultimately killing Kefka; a former general who's all alone in the post-apocalyptic world is the main character.
FFVII: Neoliberal nightmare; the world's controlled by one corporation, and one of their genetics experiments astral-projects his way into controlling a doomsday weapon.
FFVIII: Love story. Bad guy turns out to be possessed, and you have to go to the future to stop her.
FFIX: A trip down memory lane.
FFX: The church forbids technology. Like all RPG churches, it's hypocritical, dogmatic, and ruled by dead people. Only by breaking with dogma can you defeat Sin permanently.
FFX-2: Yuna tries to find Tidus, only to find that 1000 years ago he and a pop singer and summoner who looks a lot like Yuna were lovers. His ghost's still around; instead of destroying Sin, he now wants to destroy the planet.
FFXI: MMORPG. Basically D&D with thousands of players.
Tactics: Middle Ages. God turns out to be the devil.
FFTA: You go through the looking glass into a world of your best friend's creation, and eventually have to kill his mother/djinni.
Oh, I forgot to mention the other rule to jagds. If you're dead at the end of the battle, you stay dead. Always include two or three people who can revive, along with anti-instant death equipment.