Dagger and Zidane. Needs psychiatric help, Dagger fell in love with her kidnapper, not healthy espescially given his attitude.

Tidus and Yuna. Yuna had no personality, and Tidus seemed closer to both Rikku and Lulu.

Rinoa and Squall. Squall didn't care until she went into a coma, woulda been okay if they hadn't put so much focus on it.

I vote Cloud and Tifa, believable, and they actually seemed to care about each other.