Vegito

Considered the single most powerful character in DBZ, Vegito is the result of the potara fusion of Goku and Vegeta. We see Vegito in the late Buu Saga when Goku returns from Other World. Vegito handles Buu with great ease after going Super Saiyan 2. However, Vegito is extremely cocky, and merely plays with Buu rather than getting to the point and destroying him. At one point Buu manages to turn Vegito into a piece of candy, but Vegito manages to beat Buu up so much while he's a piece of candy Buu has to change Vegito back to normal. Vegito continues to waste time toying with Buu until Buu manages to absorb the fused Saiyans. Although the fusion is supposed to be permanent, Buu's magical enzymes cause Vegito to un-fuse. Once they are separated, the satisfied Vegeta removes his earring and crushes it in his fist.