I couldn't bring myself to finish FF XIII-2 but I didn't really dislike what I played. I gotta go with Final Fantasy VIII. I was so stunned by the intro and the promise of a love story. Didn't really enjoy the game or the story at all. I think I got to the part where everybody suddenly remembered that they used to know each other. I was young and didn't really have high expectations for video game writing but I think my reaction was "REALLY? You gotta be kidding me!". The gameplay wasn't very fun to me, either. I liked the card game, though. I was obsessed with it until the rules went all crazy.
I'm not going to pretend I played them all. I first played VII, then went back to VI (aka III), VIII, IX, X, X-2, XII, XIII, and XIII-2 and I played on on DS that I couldn't finish. I played a few spinoffs too like Ehrgeiz, Crisis Core, and Tactics.
