Cell and Namek saga are Toriyama-sensei's masterpieces, So beautifully written and of course the artwork. The Android and cell saga in particular, had many mature themes and tension. Trunks and Time travel, His mentor being Gohan the only survivor of the Z Warriors, Being killed off in the future, Looking back it only made sense for Gohan to be the hero who defeated Cell but he was still able to make Goku, Vegeta, Trunks and everyone else be heroes and feel important to the story as well.