Sasori: All he wanted was to become a perfect puppet. He had to cope with his parents dying at a younge age, and made Two Puppets that looked like them. Then later on in life he let himself die by the hands of those same puppets who looked like his parents.
Asuma: Simply because he died without ever getting to see his child come into the world, and died being able to say goodbye to his students.
Deidara: JK, his wasnt sad it was badass.
Itachi: At first his death wasnt sad, but after Tobi told the truth about Itachi, you couldnt help but feel pity for him. He suffered for years with a sickness just so he can die by the hands of his brother.
Neji: was able to die knowing he save the person who helped him realize not everything is about destiny, and being able to die protecting his comrade.
Haku & Zabuza: No words needed.
Jiraiya: killed by the student who he thought could become the child of the prophecy, and couldnt even say goodnye to his student. As well knowing he knew that he might die going there but did it anyways.
Asuma: Simply because he died without ever getting to see his child come into the world, and died being able to say goodbye to his students.
Deidara: JK, his wasnt sad it was badass.
Itachi: At first his death wasnt sad, but after Tobi told the truth about Itachi, you couldnt help but feel pity for him. He suffered for years with a sickness just so he can die by the hands of his brother.
Neji: was able to die knowing he save the person who helped him realize not everything is about destiny, and being able to die protecting his comrade.
Haku & Zabuza: No words needed.
Jiraiya: killed by the student who he thought could become the child of the prophecy, and couldnt even say goodnye to his student. As well knowing he knew that he might die going there but did it anyways.