I - The Basic Final Fantasy Game. Fast Moving, Good Feeling Battles.

II - The Battle System Is A Little Stiff, But You Get Used To It. Good Overall Game.

III - Probably One Of The Best Oldie's. Class System, Lots Of Towns And Dungeons, More In Depth Story.

IV - The Absolute BEST Old FF Game. Has A Well Thought Story And Loveable Characters. Battle System Is Amazing.

V - Faster Paced Battles, Better Monsters, Compared To The Previous Game, This One Isn't So Good.

VI - A Repeat Of Before But With Better Stories And More Added To The Battle Sequences.

VII - The Pinnacle Of Final Fantasy. The Best FF Game There Is. Incredible Story, Loveable Characters, Tons of Side-Quests.

VIII - Trying A Bit Too Hard To Repeat The Success Of The Last. Mostly About Love. Either You Loved It, Or Hated It.

IX - The 'Under-Rated' FF Game. Had The Potential To Possibly Be Ranked Up With FFVII. Criticized For 'Kiddy' Graphics.

X - The Most Well-Known FF Game Now A Days. Features Many New Upgrades To The Old Games. Ex: Sphere Grid, Blitzball.

XII - A Risky Move By Square Enix. Redid The Battle System, But Seemed To Pull It Off Nicely. Tops It Off With A Good Story.

Hope I helped. :D