Bra
Bra is Vegeta and Bulma's second child. Bra doesn't have much of a role in Dragon ball Z or Dragon ball GT. She can control a ki (which is seen when she flew to help bebi) She never transforms into a super saiyan though. She can make vegeta do whatever she wants!

Bulma
Lets put it this way.... NO Bulma No DB series! She created the dragon raidar which helps everyone find the dragon balls. With out her Krillin and Gohan would have never gone to nameck, which means goku would have not turned super siyan, and there goes the world. Trunks would not have come from the futer , to help and warn the Z crew about the Androids...he wouldnt even have existed with out her! Bulma gots her father's brains, and her mother's looks.

Trunks
Futer Trunks/Mirai no Trunks- Another important fellow right here. He is the son of Vegeta and Bulma. Trunks come's from the futur...this one atleast.. he warned the Z team about the androids and helped out to kill Cell. He trained with his father in the hyperbollic time chamber. He also kills frieza and king cold. He carries a sword given to him by Tapion.
Trunks- He is the best friend of Goten (Goku and Chichi's second child) Trunks is a little stronger then Goten. He transforms into a super saiyan which made Vegeta mad a bit. Trunks fuses with Goten to make Gotenks (he does this to avenge his fathers death with buu). In GT He stops training cause he says its too boring but when the black star dragon balls have got to be found he joins goku in the search.

Vegeta
HAH!! The proud Prince Vegeta! He travels to Earth to find the Dragon balls after hearing it from Raditzs' radar thingie. He went and got deafeted by Goku. He returns and gets healed at planet no. 79, then heads off to Planet Nameck to get their dragon balls. Vegeta wanted the dragon balls so he could wish for imortality. His wish is never granted. During the android saga he had a kid with Bulma when he was "training" to fight the androids. After that, he becomes a little bit more civil. During the Buu saga he sacraficed himself to save his family and the world, They used the Nameck dragon balls then to restore the earth and all those killed by buu except for the evil ones. To everyone's awe, Vegeta was brought back!! He isn't evil after all!! He still wants to fight Goku for his first lost through out the whole series.

Granny and Grampy’s

Mrs. Briefs
The so happy, it’s sickening, mother of Bulma. Mrs. Briefs holds an extremely small role in the whole series. Mainly she likes buying cakes and offering everyone tea, or drinks. She is um…very…un-intelligent. She isn’t near as smart as Bulma and her husband, The only good thing about her is that Bulma gets her looks from her.

Dr. Briefs
The father of the one, and only, Bulma. He doesn’t play a big role in DBZ he just makes stuff. He builds three ships used by the Z gang during DBZ and he helps repair Android 16. He is a very friendly guy who had a little cat like thing who flies around his head or something. He had lavender hair.

King Vegeta
King veggie is the father of that proud prince we all know and love. He decided to keep his son rather then blast him of to conquer a planet unlike most saiyans do. He hated Frieza so much he gathers all his elites to go and kill him, when Frieza is attempts to destroy Planet Vegeta. He is very strong but is easily killed by Frieza with only two hits. After that he kills everyone and destroys the Planet Vegeta. ::sniff::