Goku. End of Dragon Ball? Goku. Beginning of Z? Goku. After training with King Kai? Goku. Any time after that? Goku. Literally the only time any of them could beat Goku is before Goku fought Piccolo at the World Martial Arts Tournament.
All very good options. Seto Kaiba's ego should have been a forerunner though. But Goku all the way. Space alien genetically programmed to destroy planets with lasers and fists, taught martial arts from two of earth's strongest, one of Namek's strongest, a genie, and one of Heaven's four greatest teachers.
goku can destroy stuff fairly easily
luffy is stupidly confident in alot of ways, he would survive stupid stuff from what i would guess
gary oak, now this is kinda meh, but his awsomeness in the series just got wtf, almost legend really, so lawls
naruto...to be honest i got nothing for him, last i remember(shippiden episode 70's of the anime to be exact) he dosent exactly have the destructive capability unless hes 9 tails to match luffy or goku
As much as I would want to vote for Gary for the lulz, power wise, Goku would win. He can pretty much blow up the planet and breathe in space... The others just can't compare, he's that overpowered.
Fist fight. Fact is without super powers gary oak will win.
As much as I wanted to say Gary (MUTHAFUCKIN') Oak, because of the ultimate rule that main characters in most anime cannot die unless he's a villain(like Death Note), he'll be the first one to lose, sadly.
Although people say that shit bounces off Luffy so he'd win because he'd be invincible, but Goku can still fight after he dies, so I'd say Goku.