Goku has faced a lot of foes through the course of the Dragon Ball series. Despite being at loggerheads with these individuals, Goku has managed to win them over with his friendly demeanor and unrelenting attitude.
5 foes that Goku turned into Allies
#1 - Beerus
Beerus was one of the most formidable opponents Goku faced in the entire series. Despite besting Goku in combat, the God of Destruction admitted to using all his power to fight the Saiyan. Beerus was impressed, and the two have got on quite well since.
#2 - Freiza
This was a very unlikely alliance that Goku had to forge for the sake of Universe 7. During the Tournament of Power, the fate of all the universes hung in the balance.
Goku has to turn to one of his deadliest foes, Freiza, to fight alongside the Z-warriors. Even though it was difficult for Goku to trust Freiza due to their complicated history, Freiza proved to be an important ally.
#3 - Piccolo
Piccolo was one of the first allies that Goku gained in the series. The Namekian came to Earth to kill Goku but eventually helped him defeat Radits, albeit killing Goku in the process.
After Goku's death, Piccolo had a change of heart and went on to help train his son, Gohan. He has since become one of Goku's most important allies.
#4 - Vegeta
Vegeta and Goku are polar opposites of one another. This is a common anime trope, which has since been seen in other shows like Naruto.
Goku and Vegeta are two of the most powerful fighters in the entire Dragon Ball series.
The two got off to a very rocky start. They were bitter enemies but put their differences aside once Goku bested Vegeta.
Vegeta's entire story arc is based on getting stronger than Goku in the Dragon Ball series. The two constantly challenge each other, which ultimately helps them both to reach their maximum potential.
#5 - Broly
Although Broly isn't an ally per se, he does admire Goku. Goku shares the sentiment when it comes to Broly as well.
After their final fight, Broly escaped to Vampa to avoid being killed by Gogeta. Goku then arrived at Vampa with two senzu beans and some capsules to help Broly heal himself.
Before parting, Goku offers to train with Broly, which is the greatest sign of respect between Saiyan warriors. The cherry on the cake was when Goku asked Broly to call him Kakarot.