Is Goku The Strongest in the Universe?

Vegetto is the strongest in the universe with the exception of non-canon Gogeta. Unfused, Goku is still stronger than Gohan.

Also, Gogeta, is at most equal to Vegetto if he does not go beyond Super Saiyan.

EDIT: Gohan was stated to be the strongest non-fused character in dragon Ball and he kicked the crap out of Super Buu that Goku was to scared to fight.

In order Words Gohan is the strongest in the Dragon Ball universe.