#1 Gohan vs. Perfect Cell
If there was one fight which stands above the rest it’s this one.
Goku heads into the battle with Cell knowing he can’t defeat him. He even sacrifices his own life for the 2nd time to save the Earth and his friends from dying. He was actually counting on his son Gohan, the gentle warrior who doesn’t like to fight yet is extremely capable of it to save the day. Everyone looked at Goku like he was crazy and not even Gohan himself trusted his own abilities.
But when he was pushed against a wall, seeing his friends hurt, and seeing Android 16’s head get crushed underneath Cell’s boot he snapped. Gohan ascended and became a SSJ2 unleashing his full power against the “perfect” fighter.
Finally, having a worthy opponent, the two duke it out before one of Gohan’s arms just give in. In a final between two energy beams, we see Gohan with one working arm and a torn shirt, his forehead bloodied and his friends giving it their all (with some last minute heroics by Vegeta), when in one final push, remembering his father’s words, Gohan obliterates Cell out of Earth’s orbit and collapses to the ground as a hero.
If DBZ ended right here we would NOT have been disappointed at all. Son passes father and Gohan saves the world. The best fight in the Dragon Ball series.