FFVII-Zack, because he dies
-Genesis/Angeal...because they think of themselves as "failures"
-Cloud, just becuase he doesnt really know who he is

FFX/X2- Tidus and Jecht, because they are taken from their home...plus jecht is sin and i feel sorry for both of them
-Paine, she...ok i just think her story is sad...since she almost dies
-Lenne/Shuyin, classic love story, except for the fact that he is a ghost and holds a grudge
FFXII- Ashe, she lost everything...poor girl