So we all know Goku only killed two characters in Dragon Ball Z... (Kid Buu and Yakon) but what happened to the little kid from Dragon Ball that just didn't care and had no qualms about killing off damn near the entire Red Ribbon Army...
Over all though doesn't hold a candle to Vegeta's impressive kill count. Who never decided to start holding back like Goku. Not to mention that other than Kid Buu, pretty much every character Vegeta killed off was stronger than Goku's opponents. :p
Technically I guess you could say Piccolo took out the strongest guy if you count Goku. I think Vegeta's jealous. :p
Gohan's kill count isn't high, but adding Cell in there at least he's not a total punk... He used to be cool.
But it looks like it runs in the family, Trunks has a much more impressive kill count than Gohan... kinda like Vegeta over Goku... But who's to say why? *cough*(vegetas family is cooler)*cough*
And then there's Yamcha, I personally don't remember him killing anyone.. ever... Hahaha, thats all I have to say about him. ^_^