Gokou
Gokou a.k.a. Kakaroto is the main character in Dragon Ball Z, his first knowledge of his real name and race came from his brother Radditz. Not only is Gokou an excellent fighter but he is a born leader. Throughout the series he inspires many people including his sons Gohan and Goten and his former rival Vegita. He is a hard worker who never backs down from a challenge. Even though with the defeat of Frieza he had become the most powerful fighter in the universe he still strives to become better. Even when Trunks warned him of the anderoids and Dr. Gero he still chose to wait and fight the anderoids instead of taking out Dr. Gero. He has only given up once to my knowledge and that was in his battle with Cell.