Family-Bardock(father), Radtiz(brother), Chichi(wife), Gohan(son), Goten(son)
Goku is the first charater we see in Dragonball, and he is the main character. We first see him as a young boy searching for dragonballs ans escaping and fighting evils. In Dragonball Z he has a son named Gohan who he named after his "Grandfather" and a wife named Chichi. He then learns he's from a race known as the Saiyans thanks to Raditz, his big brother, and some added assistance from Nappa and Vegeta in the Saiyan Saga. Then in the Frieza Saga, he fought the Ginyu Force after training in 100 times normal gravity and easily defeated them. Then on to Frieza. Frieza had the upper-hand, but then Goku threw a huge Genki Dama at Frieza. Frieza then came back and killed Krillin. This set Goku off and he turned Super Saiyan and easily defeated Frieza. In the Android Saga, Cell was about to blow up earth, than Goku teleported him and Cell to Kaio's planet. They all died, except for Cell. Goku then encouraged Gohan to become Super Saiyan 2, easily defeating Cell. In the Buu Saga, He fused with Vegeta to form Vegetto and destroy Buu. Finally in DBGT, when fighting with the evil Shenlongs, he went Super Saiyan 4. He wasnt strong enough though for the 1 star dragon, So he fused with Super Saiyan 4 Vegeta to form Super Gojita who beat up the Shenlong pretty good.
Interesting Facts: Goku's saiyan name, Kakorott is a pun on carrot. Goku is the only one to go through all known forms of Super Saiyan. Goku swallowed a black star dragonball to finally defeat the evil shenlong of dragonball number 1. At the end, Goku rides on Shenlong's back and is never seen again by anyone but Pan.