Welcome To Z Fighters.

Z Fighter History.

The first actual formation of the Z Fighters was out of necessity, brought on when Goku was faced with Raditz, who had kidnapped his young son Gohan, and wanted to destroy the Earth. Goku formed an alliance with his arch rival Piccolo in order to fight for a common cause. The alliance made from necessity is considered the true birth of the Z Fighters. The battles against the Saiyans, Vegeta and Nappa, is commonly considered the first time Earth's Special Forces engaged enemies together. During the conflict on Namek some months later, Earth's Special Forces would ally with the Namekian race against Frieza and his World Trade Organization, this part of the series would be a crucial moment for the forces, as they now would gain the support of their once enemy Vegeta, and that Piccolo had finally changed completely for the good. This is also the first time in the series in which a character actually refers to the group as the Z Fighters, when Gohan pleads with Chi Chi to be allowed to go to Namek with Krillin and Bulma. He informs her that he too, is a Z Fighter, and must be there to protect his friends.
Also worth noting is that unlike the Android Saga, the Majin Buu Saga is when Vegeta voluntarily became a "good guy". He fought for his family, and to save the Earth, even sacrificing himself in an attempt to kill Majin Buu. He also later came up with the idea of Goku using a Super Spirit Bomb that defeated Kid Buu at the very end. Ten years following Buu's defeat, Goku leaves to train the monster's reincarnate, a young boy named Uub, whom he hopes will become Earth's protector.
During Dragon Ball GT, the main fighters for the most part tend to be Goku, Trunks and Gohan's daughter, Pan. Uub does fight in the first major arc, the Baby Saga. However, the "Z Fighters" (Or "GT Fighters") do come together in the Super 17 Saga. While Goku's trapped in Hell, Android 17 kills Krillin. This forces the hand of the last major, briefly retired fighters from the end of Dragon Ball Z. The following are the fighters who fought against Super 17: Vegeta, Trunks, Goten, Gohan, and Uub. When the Shadow Dragons appear, Goku defeats the majority, only to finally be outmatched by Syn Shenron, who later becomes "Omega" Shenron. Vegeta arrives and with Bulma's help transforms into a Super Saiyan 4 himself, allowing him and Goku to fuse into Gogeta. Their fusion eventually wears off, and Goku is nearly killed. The final effort of the warrior team is against Omega, in which Vegeta, Gohan, Trunks, and Goten attempt to fight him, despite all failing miserably. Goku eventually returns and kills Omega with a Universal Spirit Bomb. Goku later leaves with Shenron, thus ending the team forever.