Krillin isn't really a slouch. People call Tien and Krillin useless, but they never really are. Especially Krillin. I always liked how Krillin was ride or die and always there for the team even when he was outclassed. Dude fights Freeza form 2 AND cuts off his tail. Who's the only other person in that fight to do that to Freeza? Fucking Goku with his Spirit Bomb, that's who.
That said, Gohan has always been my favorite. He always had these OMG
moments like when they first get to the Namek and see Dende and his brother being terrorized by Freeza and his men, and jumps in and kicks the SHIT out of Dadoria despite it being a practical death sentence. Then when Freeza stabs Krillin, Gohan goes ALL OUT with awesome. Gohan goes from a baby who's lost in the woods and stuff to this hardened warrior in less than a year. I fucking love that character.
And then Toriyama turned my man into a fucking nerd loser while Goku and Vegeta get the cool new power ups adlkfjas;dfkjs;dfj;sfkdsajf;lksadfap;skfjas'd
One thing I like is about Dragon Ball is that even the "weak" characters have helped a lot down the line. Tien learns mabufu or whatever. He and Chaotzu both show the gang how to fly which is the single most useful technique in the series. Every character starts using Tien's moves too, like Solar Flare, and it has always proved useful. Even Ooolong and Puar have helped over the years. Yajirobe takes out of Piccolo's dudes in one hit, helps Goku climb Korin's Tower when he's near death, AND cuts off Vegeta's tail.
The only useless character is Yamucha.
