Gotta say, debating who’s the strongest Saiyan in 'Dragon Ball Z' is one of my favorite internet squabbles — it’s the kind of fan argument that makes me rewatch fights and pause-frame energy blasts for fun. If you’re strict about 'within the confines of DBZ' and you mean individual, non-fused Saiyans, there’s a clear arc: Goku ends the series as the top individual Saiyan. He pushes into Super Saiyan 3 during the Buu saga, a form that multiplies his power far beyond what Gohan achieved at his Cell Saga peak. Gohan’s burst as Super Saiyan 2 during the Cell Games is legendary — emotionally and mechanically he eclipses everyone in that moment — but he doesn’t maintain or build on that peak in the Buu arc, whereas Goku keeps training, refining techniques, and learning to use larger transformations.
If you include fusions, the waters get deliciously muddy. Vegito (Goku + Vegeta via Potara) appears during the Buu saga and is basically a walking mic-drop; he casually dominates Super Buu in a way neither Goku nor Vegeta could on their own. Gogeta isn’t in the original series proper, but canon debates aside, fusions are absurd multipliers. Then there are movie Saiyans like Broly — his power in the films is off the charts and terrifying, but his status in the official DBZ continuity is shaky. A fair breakdown I often use when arguing with friends: solo peak = Goku (SSJ3) by series-end, solo peak moment = Gohan (Cell Saga SSJ2) in terms of one-time dominance, and if fusion counts = Vegito (hands down) or Gogeta depending on which media you accept.
Beyond raw power, I love considering potential and personality: Vegeta’s brutal drive and tactical growth make him a perpetual threat, Trunks brings unique experience, and Gohan’s latent power is a fan-favorite what-if. At the end of the day I pick Goku for DBZ’s timeline — his consistency, training, and iconic transformations make him the standout — but I’ll happily argue that Gohan’s Cell-era moment is more emotionally satisfying. Either way, this series keeps me hyped for every rematch and what-if scenario, and I’ll probably never stop cheering for both Goku and Gohan in their best moments.