Goku- He is the main Character in Dragonballz. He meets raditz in the first part of the show. He is killed by Piccolo in the fight against Raditz and goes off to train with King Kai in the other world. After he is wished back to life he fights Vegeta and Nappa on Earth and defeats vegeta who is spared. He goes on to fight freeza on Namek in the Frieza saga. He supposedly kills Frieza and then dies in the explosion of Namek but he and Frieza survive. He learn the mive Instant Transmission on Yardrat and then returns to Earth. He contracts a strange heart disease in the android saga but recovers thanks to the medicine brought by Trunks. He trains with Gohan in the Cell Saga and fights cell and almost wins but is killed in the explosion caused by cells self destruction. He takes part in an other world tournament and wins by defeating his oppenent Pikkon. He is the strongest in power and in will but that also changes through the show.
Vegeta- He is the saiyan prince. He has a big attitude toward others. His first appeirance on the show was when he confronted goku and his friends. He thought that he was the strongest being alive but when Goku defeated him this angered him greatly. He promised revenge. Later he sought out the dragonballs on namek to gain immortality. He almost achievd that goal if it had not been for my man Gohan and Krillan. He later fought against Frieza and died. He was brought back by a wish from the dragon and trained to also become a super saiyan. While goku is gone he succeeds in becoming one and challenges the androids. He defeats android 20 easily but later on when he fights 18 he is defeated easily. He trains with his son Trunks and becomes extremely stronger, almost level 2. He never gets the chance to fight 17 because he is absorbed by cell but he does get to fight cell. He allows cell to absorb 18 to become perfect and by doing this is now again the weaker character in the show. After cell is defeated by Gohan, and Goku is now dead, he trains for the day he may fight Goku again..
He is the favorite character among alot of people. He first shows up in DragonballZ when frieza has just reached Earth. Suprisingly to everyone he transforms into a super saiyan and defeats frieza and his father easily. Afterwards he takes everybody to a spot where he says goku will be arriving soon. Goku does arrive and Trunks asks to speak to him alone. Before he can tell what he came to say he tests Goku's power in a small short match. Goku is able to block his attacks with his finger. Then Trunks tells that he is from the future where evil androids have taken over the Earth everyone but Gohan is dead. Also that Goku dies by a heart virus. He then gives Goku the antidote and tells him when and where the androids will appear. After that he leaves back in his time capsule. He shows up later after Vegeta has defeated the first android to tell them that those aren't the real androids. They find them later when they are released and find that all together they are no match for the androids. Vegeta and Trunks then go to the Hyperbolic Time Chamber to train and become strong enough to defeat the androids. They do but vegeta then allows a creature called Cell(his bio will be in th villians section)
to absorb the androids and become perfect. Then they are not powerful enough to defeat the evil android. They train again before the Cell Saga but still aren't strong enough to defeat Cell, he is killed by Cell and brought back by the dragonballs, he leaves to battle the androids in his own time.
I will put more characters but I need to work on something else.