The real question is what each fighter has actually shown, not who's funnier to imagine winning. Goku's power is backed by concrete feats: planet-shaking punches, instant transmission, energy attacks, healing, and combat skill honed against gods. Saitama's best claim is a parody gag that scales to whatever the joke needs, which isn't a measurable ability. In a tournament, you judge demonstrated tools and limits, not infinite hypotheticals. The other side has to prove Saitama can tank a serious Kamehameha or keep up with instant transmission. Until they do, Goku wins.