I would personally say
Nariko - She was treated like an outcast and was told that she would be the end of their clan, and no one truly saw who she was until the end.
Kratos - His entire life was for revenge against the gods and when he finally accomplished what shought vengence for, he really had no idea what to do with his life and then
Cole - Depends on what ending you chose for inFamous and inFamous 2
Raiden had it pretty bad. Child soldier and having his mind and reality effed by the Big Shell incident, then sinking into a deep depression, feeling too ashamed to be near his family any longer, becoming mostly machine and believing he had no purpose other than to kill, getting beat up really badly several times (losing limbs etc), then in Rising getting maimed again. Oh and presumably losing Snake sucked.
A turbulent life.