Most people find Rue's death to be by far the most emotional part of "the hunger games", I agree that it is very emotional but i think the bit following her death when Thresh finds Katniss triggers emotion as well. "Conflicting emotions cross Thresh's face. He lowers the rock and points at me, almost accusingly. 'Just this one time, I let you go. For the little girl. You and me, we're even then. No more owed. You understand?'". In this part of the book, Thresh has found Katniss and is supposed to kill her according to the rules of the game. He is conflicted however, because Katniss created a beautiful bed of flowers around Rue, a small weak girl from Thresh's district, following her death. He knows that killing Katniss will better his chances of staying alive and making it out of the competition and home, however he is so moved by the love Katniss showed Rue, who Thresh was very protective of, that he is unable to kill her. Collin's makes what Katniss did for Rue something so meaningful that it could inspire a killer to let a victim live, although we don't really view Thresh as much of a killer compared to Cato or Clove, especially after we see he has emotion and compassion in this scene. By making him care so much about Rue that he would lessen his chances or survival to help someone who helped her, we want Thresh to survive as well. Now with three people to cheer for (Katniss, Peeta, and Thresh) the reader becomes even more conflicted.