Goku is the main protagonist of Dragon Ball Z (They've got a new game coming!) and, practically, the face of the franchise. Throughout the story, Goku has made many friends and enemies along the way, but his family has expanded since then as well.
Losing his birth family at infancy, traveling to an alien planet and being adopted, marrying the daughter of the ruler of Fire Mountain and then having two sons and then becoming a grandfather are all the events that have led to his family growing. And that's just the beginning, not to mention how his son, Gohan, ends up marrying Videl and having a daughter, Pan.
10 Goku is a Low-Class Saiyan
Goku's father, Bardock, and mother, Gine, were both Saiyans from Planet Vegeta. While his birth name is Kakarot, Goku was born from the relationship between Bardock, a Saiyan who was considered one of the bravest warriors on the planet, and Gine, a humble Saiyan. Throughout the first two arcs of Dragon Ball Z, Vegeta regularly states how Goku is a low-class warrior while he himself is a super elite warrior class. This hints to the fact that while Vegeta may have not needed to train from birth, Goku, who trained throughout his life, built up his strength to the point where it rivaled a super elite.
9 Gine was a Saiyan who didn’t fight
Saiyans are a warrior race that have a high aptitude for battle and enjoy fighting or destroying. While Bardock was a fighter, Gine was his polar opposite as she lacked a high enough battle power and didn’t share the thirst for battle like the average Saiyan.
Instead, Gine, with other Saiyans such as herself, were tasked with menial labor, of which, she took part in meat distribution. Though it may not have been a job that grabbed her everyone’s respect as a warrior, it was still an important job considering the amount of food the species consumes.
8 Goten was born as a natural Super Saiyan
During the Cell saga, Goku and Gohan remained in their Super Saiyan form in order to adapt to its energy drain and make it more efficient for use. Goku did not meet Goten until the Buu Saga, which means that Goten was conceived during the resting period of ten days before the commencement of the Cell Games.
By retaining his super Saiyan form throughout this period, Goku inherently passed on the super Saiyan trait due to the increased proportion of “S-cells" in his body. Goten was born genetically enhanced with a high proportion of S-cells in his genetic blueprint, allowing him to transform easily.
7 Bardock and Gine were in love
The Saiyan males and females only chose mates for breeding purposes, and the relationship seemingly only lasted until the survival of their race was ensured. Gine, being low powered and gentle, was already labeled as an outlier among the Saiyan culture.
However, her relationship with Bardock was genuine and a rare case among all the mates as both of them were wed and remained in love with each other, rather than only for breeding purposes, or because both saw thought that the other was strong and powerful.
6 Goku married for food
After accidentally killing his adoptive father, Gohan (also called Grandpa Gohan), Goku was left a bit naive in regards to how the world works. Therefore, his weak grasp on societal norms and lack of understanding led to him promising to marry ChiChi when they were both young.
During the Martial arts tournament, after many years, ChiChi battles Goku, and after being defeated, reminds him of the promise he made so long ago. Goku responded by saying that he thought marriage was some sort of cuisine at the time and agreed only because he was famished. Nevertheless, he still agreed to uphold his promise to ChiChi and married her.
5 Every family member has died once
Every single member of Goku’s family has died at least once. His mother, Gine, died when planet Vegeta exploded and his father, Bardock, died when he was disintegrated by Frieza's supernova attack. His adoptive father, Gohan, met an unfortunate demise when Goku transformed into his Oozaru(Great Ape) state and stepped on him.
His brother, Raditz, and he himself fell victim to Piccolo's Special Beam Cannon attack in the Saiyan saga. ChiChi was transformed into an egg by Buu while Gohan and Goten blew up with the Earth. His granddaughter, Pan, died when Frieza blew up the Earth at the end of Resurrection F.
4 Married into Royalty
Many fans are unaware of the fact that though Ox-King only ruled over a small kingdom consisting of Fire Mountain, he was a king nonetheless and by definition that makes ChiChi a princess and Goku, a prince. So basically, like Vegeta, who is royalty but born into it, Goku is also technically royalty but was married into it.
Though they may be prince and princess of basically nothing, on account of all the Ox-King's treasures and belongings being burned down, the same can be said about Vegeta who only rules over Goku and his children on account of them being the only survivors.
3 Pan has the potential to be the strongest
Throughout the series, it has been hinted that half-breeds or hybrids have a greater potential and fighting aptitude than pure Saiyans.
Both Gohan and Trunks were able to surpass their fathers in the Cell saga, where trunks powers up more than Vegeta during their preliminary fight with Cell and Gohan became the first person to achieve the Ascended Super Saiyan or Super Saiyan 2 transformation after only unlocking the Super Saiyan transformation less than a year ago. Pan is shown to even be able to fly as an infant who barely knows how to control ki, or know what even ki is.
2 Cousin Cell
The one and only bio-Android in the Dragon Ball Z series, Cell, was created by the brilliant Dr. Gero in order to make the perfect fighter. Cell, as his name applies, was genetically crafted from the multiple collected DNA samples from some of the world's greatest fighters.
These samples included the DNA of Piccolo, Frieza, King Cold, Krillin, Vegeta, Goku, and Gohan, granting him incredible strength and amazing abilities. Since Cell contains DNA from both Goku and Gohan, it makes him a blood relative of the family- more on the side of a cousin of sorts.
1 Goku has zero interest in his real parents
Being born on Earth under the adoptive care of Grandpa Gohan, Goku grew up knowing only Gohan as his parent. When the question was peaked as to why he never questioned Vegeta about his true heritage, Goku's reply was that he simply doesn’t care.
His perception towards Saiyans has also been slandered after his own brother took his son, Nappa killed his friends and Vegeta, for two arcs, went on a murder spree. So now Goku considers himself a Saiyan from Earth. His identity is tied to his humble beginnings on the green planet, rather than planet Vegeta.