I've always had a preference for Balma, it's unfortunate she becomes less and less important as time goes on and the characters outgrow the need for tech. She's a genius inventor, though!
Granted, I've always had a preference for female characters, which isn't exactly DBs strong suit, lol. Now that I think of it, whatever happened to Launch, that lady with the two personalities? Did she just... disappear in DBZ?