Bardock: Bardock the father of Goku and brave and strong warrior at that. Appearing in the movie Bardock "The Father of Goku". Sent on a routine mission to the planet Kanasa with his fellow comrads, they took over the planet in there transformed states(giant apes) but when they thought they had done it and were sitting around teasing Bardock about not knowing anything about his son. The leader of the Kanasans came out from all the rubbish and within a split second hit Bardock on the back of his neck and transfered the power to see the future to him, the power that Frieza wanted for himself. Haunted by visions of his own end as well as the destruction of his entire planet, he sets out on a nightmarish race with fate to avert the impending disaster. But first he goes to aid his comrads who had left before him; he met fate and it slapped him in the face as he saw his comrads on the planet Nete dead even the closest ones to him and strongest Fasha and Tora. All killed by the elites and Dadoria. Well as Dadoria took care of him or so he thought. Bardock confronted Frieza and may I say was the stupidest thing he had ever done and he payed for it by getting killed and all his entire planet detting destroyed. But Goku got released just in time and off lerking in the shawdows was Koola Friezas brother but that is another movie.
Also included: Nappa,Vegeta,Zarbon,Dadoria,Baby Goku
Gohan: Gohan is the powerful son of Goku. Mixed with human and saiyan which showed to be a very good combo. He first appears on the first episode of DBZ "Arrival" he seemed to be a bit of a punk, but he had a powerlevel of 713 higher than anyone in the series except for Radditz at the time. Held back by his mother in the art of fighting he didn't really know how to use his power correctly. But he showed Radditz in the end when he dented his armor. From then on he used his power to his advantage. When he beat up on all that came up against him. But his power only came in spurts when he got angry. This anger fueled him to the point where he went SSJ in the hyperbolic time chamber. And he proved to be a good adversary in 'The History of Trunks". And in the Cell saga he proved to be even more powerful as he went SSJ2 because of the death of Android #16. Then he beat Cell. Gohan has to hold back his power a lot in the series because of his mom but when he gets started his enemy pays there toll. In the Buu saga he shows that he is a force to be recon with. As he come back fully powered up by the Old Kia(15generations of Kia) and comes to the rescue of Goten and Trunks and Piccalo. That was probably the peak of his power in the entire series. In GT he becomes more of a scholar than a fighter but when something had to be done he stepped in. For example: his amazing power as he protected Goku as he went SSJ4 for the first time. Bassically Gohan has the most raw ki(power) in the entire series and proves that.
Interesting fact(voice played by women on Funimation releases)
Goku: We first meet our heroe in the first episode of Dragon Ball he meets of with a new character searching for the dragon balls. As Goku and his new allie Bulma set out to search for the legendary dragon balls they meet some interesting characters. And they all get a taste of Goku magnificent powers. From the 1st saga of dragon ball to the last Goku is marked as a boy with un-fathamable powers. As he enters the 23rd Tenkaichi Budoukai he almost wins against his master who had come a Jackie Chun. From then on he displayed his nice powers defeating Piccalo in the 24 Tenkaichi Budoukai and even defeating the entire Red Ribbon army. As he progressed he into a true man he encountered even more enemy's. The first was Radditz who picked Goku apart. But from that experience on he learned his lesson, and went to the other world to train under the legendary King Kia. Coming back with the ultimate power to beat the evil Saiyan Vegeta and Nappa. With a battle power un-surpassed by anyone. Nothing could keep Goku down as his friends set off to Namek and left him behind. But that was a good thing as he traind at 100 times gravity and increasing his skill 10 fold from earth to Namek. As Goku beat down the Ginyu force with a power level of 180,000 nothing to Friezas, he took it upon himself to save his friends. After recovering his was ready for battle. And with the killing of his friend Krillin Goku was the 2nd SSJ to achieve the level the first being Brolly. As Goku proved himself he did even more throughout the rest of the series. Matching Perfect Cells strenght he was just not enough, but going into the Buu saga achieved the ultimate level SSJ3 and almost beating Buu, but being the person he is he left it up to Gotenks. As he came back to earth and upgraded to Gogeta he showed Buu a hard time. Goku's strength can not be matched by anyone's because it's not how strong you our it's your warrior spirit. When he beat Buu with a Super Genki Dama. He proved that he was the strongest fighter in the universe. And as he took Uubu as his pupil he passed his talents onto another great warrior. Goku has surpassed every exspectation put in front of him and his the ultimate warrior. For example keeping his true power in GT as he was turned into a young Goku he showed his enemy's. SSJ3 being to much for his little body to handle, he took it up to the next level and achieved the last level SSJ4 and beat Super Cyborg 17 and with the assitance of Pan beat 6 of the 7 Evil Shenrons. Until Pan gets possed by Chii-Shenron, and Goku sheds the tears of 10x's kamehame-ha. Him and Vegeta having to upgrade to become SSJ4 Gogeta after Vegeta goes SSJ4 because of Bulma's brute ray. After Goku and Vegeta diffuse Vegeta and Goku eventually kill Li shenron, because Goku swallows the four star dragonball. After the battle the 7 dragon balls get absorbed into Goku, as he rides on Sheron's back and vanishes into the sky. Goku is truly the most powerful fighter in the universe with mind, body, and soul.
Pan: the daughter of Gohan and Videl. She is a real pistol, her whole life is fighting alongside her grandfather Goku. She first appears in the last 2 episodes "I'm Uubu. Now 10 years old, formely Majin buu..." and "To become stronger! Goku's dream is to surpass it!!" in the Tenkaichi Budoukai. She wipes the floor with Gohan and her first opponent who believes he can't fight a little girl but he learns his lesson the hard way. She never goes SSJ but she is just as good. In the GT series she is the first person to see her grandfather in his small form. And then they go out on a big hunt through space to search for dragonballs. When the evil shenron's split her and Goku were along side fighting the evil shenrons. But as the luck runs out she is killed by Chii-Shenron posses her and she dies. But she appears again in a special at the end of DBGT. Overall she is one of the best fighters in the GT series.
Trunks: First appearing in the Trunks special as a older version of himself. He is taught by Gohan in the future to beat the androids that were destroying the planet. But after seeing that they were to much he gave in to not being able to beat them even as a SSJ and went into his mothers time machine into the past to save the z warriors and to give Goku the antidot to live and beable to beat the androids. People think that Goku beat Frieza but it really was Trunks after he came to the rescue upgraded to SSJ and sliced all of Frieza's men, Frieza, and King Cold in to pieces and obliterated them. After seeing that Goku was more powerful than him he gave him the antidot and left only telling Goku the big secret that he was the son of Vegeta and Bulma, but Piccalo overheard it also. After leaving he didn't come back until the androids 17 and 18 emerged again. He wasn't of much use but he did his part. After the training with his father in the hyperbolic time chamber he eventually surpassed his fathers strength and went SSU against Perfect Cell. But not being of much help because all of his raw strenght slowed down his speed. After the defeat of Frieza you don't see the warrior anymore. Until his chibi version grows up to become a SSJ at the age of 8. After competing in the Tenkaichi Budoukai against Goten and winnig he goes on to fight Majin Buu as he fuses with Goten to become Gotenks a heroe who almost beat Majin Buu but time ran out. After getting absorbed you don't see the warrior again until close to the last episode. Where he is grown up about the age he was when he first appeared to beat Frieza. Well he takes place in another Tenkaichi Budoukai but doesn't get to fight because of the interruption of the fight when Goku leaves with Uubu. Or else he was going to fight a gay man woho winked at him numerous times. Well in GT you see him a lot the first being when the dragon balls first appear and he goes on a big adventure to search for them but gets into much trouble. After that you see him a little he doesn't do much good fighting in GT but enough to be called one of the most powerful warriors in the universe. The last time you see him is when he is protecting Goku with the others by surrounding him with ki. Well after that it's the end of seeing him. He never dies in the series which is one of the best accomplishments. Overall he is a very good fighter and he shows that throughout DBZ/GT.
Interseting Fact(appears in Trunks special)