Vegito

Vegito (ベジット) is the immensely powerful result of the fusion between Son Goku and Vegeta by the use of the Potara Earrings. His voice is a dual voice that contains both Goku's and Vegeta's voices. Vegito is regarded most for his immense power and speed, and is the most powerful character in the Dragon Ball manga and the Dragon Ball and Dragon Ball Z anime series. His Fusion Dance counterpart is Gogeta. In the Japanese version his name is spell V-E-G-E-T-T-O.

Voice Actresses & Actors
all information on Vegito came from http://dragonball.wikia.com/wiki/Vegito
 * Japanese : Masako Nozawa (Goku's voice)
 * Japanese voice actor : Ryo Horikawa (Vegeta's voice)
 * English :  Sean Schemmel (Goku's voice), Christopher Sabat (Vegeta's voice)