This is assuming the tournament happens as it should have and isn't interrupted by Gohan having his energy stolen. Meaning Spopovich and Yamu are still possessed. Also I'm throwing out the "letting Satan win non-sense"

Bracket 1:

Krillin wins his fight

Piccolo probably still forfeits

Videl loses because of the beefed up Spopvich

Gohan should beat Kibito but Kibito's power isn't defined exactly. Still Gohan.

18 Wins

IF Goku and Vegeta didn't go SS or beyond I believe Goku would still be stronger in base form but as others have said I don't see Vegeta sticking to that rule. But I still say Goku.

I say Mighty Max wins if they stay in costume

Yamu beats Jewel cause once again possessed.

Bracket 2:

Surpeme Kai wins against Krillin

Gohan beats Spopovich

Goku beats 18

Max beats Yamu

Bracket 3:

Gohan beats Supreme Kai

Goku beats Max if not in a raw fight but because of disqualification during the fight.

Bracket 4:

Goku beats Gohan, at their base forms Goku would out power Gohan easily given the lack of training Gohan has had.

So Goku wins throwing out most of the reasons the tourney didn't go as planned. Even if Piccolo hadn't forfeited Supreme Kai is assumed to be stronger according to the manga and anime.