I’d have to say kakashi was an easy last, though his childhood and life were definitely still tragic. I’d probably rank gaara number one since his dad took everything away from him, including the love of his mother and forcing the one person gaara trusted to try and kill gaara. If it wasnt for naruto tnj’ing him, I wonder what kind of monster gaara would’ve become. Sasuke would come in second because like gaara he had the love of his family (and literally his family) stolen away from him and was tortured by his brother, who he idolized until that point. But unlike gaara, sasuke still has the village there for him while he grew up. Naruto takes third, while his life was tragic and he literally spent it alone and had no one there for him while he grew up, he never suffered the same way gaara and sasuke did. He suffered for a long time and he suffered deeply, but being alone isn’t as bad as missing what it was like when you weren’t alone and as awful as it is, naruto never knew what t was like to not be alone until he was already heading into his teens