Let's start with the Final Fantasies. The ones that I've played.
Final Fantasy I: The villain is named Garland. Also the combat system is terrible. I gave up after nothing interesting at all had happened.
Final Fantasy VII: It would probably have helped their dramatic generic anime storyline if the characters didn't look like Duplos. Not even Legos. Duplos. Also the combat system is terrible. I gave up after I got killed by a pheasant that turned my party to stone. In Square's defense, it was a giant pheasant.
Final Fantasy X: The main character has 1.5 pants. The story was actually kind of interesting for a while, except for the terrible dialog. You know the part I'm talking about. So it felt like I was watching a decent anime while simultaneously playing a terrible video game. I like how the leveling system is a board game! Also the combat is terrible. Also also: blitzball. I gave up after fighting Seymour again for the thousandth time. P.S.: The entire plotline where Yuna decides she wants to marry Seymour and retire is completely out of character for her, since, y'know, she's supposed to be totally dedicated to her quest to defeat Sin.
Final Fantasy XI: I've only watched people play it, but the combat (which is terrible) involves waiting for an hour to get a group of five guys together and then spend five minutes trying to kill a fish floating in midair. If you level up, you can fight the same fish, expect they call it something different.
Final Fantasy XII: I gave up before finishing the tutorial because I didn't actually own the game and I don't live with people who do anymore. I don't remember the combat being terrible.