Goku would win. Him blasting Kid Buu off the face of the universe helped solidify that he is really one of the best fighters in the universe. I don't give a f*ck what anyone says. He defeated a psychotic little pink bastard that has destroyed solar systems(destroying f*cking Earth and all of humanity too) and is literally pure evil and whose only thought is to kill. That's pretty badass.
"At the end of the day, I don’t give a crap who’s taking what. The steroids are not going to help them when I hit them. Take as much as you like, I don’t care." - Mark Hunt