In Dragon Ball, the Goku-Vegata rivalry is one of the central story points of the whole saga. Not only does it provide an intense competition between the onetime enemies that powers the underlying story of Goku’s quest to be the best fighter in existence, but it also supplements and improves the various story arcs that run through the series. So it's amazing when Goku and Vegeta agree to literally combine themselves into one body to defeat an opponent neither could defeat on their own. This has occurred on two different occasions, meaning it's only natural that fans would wonder which of these fusions—Gogeta or Vegito—would beat the other in a fight?
The first Goku-Vegeta fusion occurrs as a response to Buu’s destruction of the Earth. To assist Goku in his battle with Buu, Old Kai gives him his Potara Earrings. The power of the earrings allows two people to combine their powers when they each wear one of the rings. Goku offers one of the earrings to Vegeta to combine to beat Buu. After initially refusing the trick Vegeta eventually consents. The resulting transformation creats Vegito. Naturally, once Goku and Vegata's powers are combined, Vegito’s powers are off-the-charts. Nevertheless, it is not a combination that Vegeta particularly likes, and when the opportunity to separate arises, Vegeta is quick to end the fusion.
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Despite his reluctance to combine, Goku is again able to persuade Vegeta that two Saiyans are better than one during their encounter with Janemba. This time, however, the fusion is not brought about by a pair of magical earrings, but rather through a special dance where both have to move in synchronicity with the other just as if they
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