Goku

Sent to Earth from Vejiitasei as an infant, Goku suffered a head injury shortly after being taken in by a kindly old martial arts master named Son Gohan. The head injury served to change Goku's disposition from a savage to mild, making him forget his Saiyan heritage, although he retained his tail and the ability to transform into an oozaru.

Goku met Bulma, ChiChi, Krillin, and all his other his other friends while in his childhood and teenage years. He married ChiChi and had a son, which they named Gohan. A few years later, Radditz appeared to reveal Goku's Saiyan past and was destroyed, along with Goku, by Piccolo. Goku then trained in the afterlife with King Kai, who did his best to ready Goku for the fight with Vegeta and Nappa. Goku returned to earth, and was beaten badly by Vegeta. He then followed his son and friends to Namek, where he defeated Freeza and was nearly killed himself, fleeing to a faraway planet when Namek was destroyed. He returned a year later to learn of the androids, and killed himself in an attempt to beat Cell several years after that. He returned later in order to battle Buu and saw his second son with ChiChi, Goten. He returned to life and began to train a strange boy named Uub at the end of the series.

Goku is undoubtedly the hero of the series, but tends to be rather empty-headed for all of his absolutely astounding fighting ability. His kind and just heart, however, often pulls himself and those close to him through their trials, allowing them to be victorious in the end.