Serious Answer:
Goku - Main character, 'nuff said.
Vegeta - Goku's primary rival throughout Z and most likely ally to keep up with him in GT/Super.
Freeza - Most iconic villain of the franchise.
Fourth spot is a difficult decision between Roshi, Piccolo, Gohan, Mr. Satan and Broly. Roshi has strong ties to the first part of the series, current events with his return to relevance and being a trope setter of the pervy old mentor stereotype that's become a staple of Shonen manga since. Piccolo also represents Part 1 and early Z and has direct ties to the series' titular orbs. Gohan was essentially the hero for the end of the Saiyan Arc and the Cell Games (as well as the early Boo Arc events), so there's that. Mr. Satan represents the gag elements of the series' early and Boo Arc tone, as well as the idea of a regular guy being able to do their part in a series full of planet busting muscle machines. Broly represents the non-canon areas of the series and his influence in Super can't be ignored.