Android 16: A prototype android that was created to kill Goku. His design indicates him with several flaws. His death triggers Gohan's transformation into SS2
Android 17: The strongest of the androids. Is the twin brother of 18. Returns in GT and is the evil character Super 17.
Android 18: Is the twin sister of 17. Later in the series, after being wished human, she marries Krillin and has a child named Maron.
Android 19: Looks like a white puffball. Has the unique ability to absorb energy through it's hands. Is killed by Vegeta's Big Bang Attack.
Android 20: Is actually Dr. Gero himself, but in android form. He is killed by 17 when he turns his back on him.
Bardock: Goku's father. Is killed by Freiza's death bomb when he plans a rebellion against him.
Bebi: Appears in DBGT. When he first arrives on earth he takes over Vegeta's body to become Bebi-Vegeta. Then after all the saiyans give him their powers after being in a trance, he turns into Ultimate Bebi. Then, somehow he turns into his ultimate form, Super Bebi. Is eventually killed By Ubuu (combined with Fat Buu), when he blasts him into the sun.
Brolli: Is the legendary SuperSaiyan, which appears every 1,000 years. Is eventually killed by Goten and Trunks, with the help of others. Was the crib mate of Goku.
Bulma: Appears in DB, DBZ, DBGT. She is the first one to meet Goku, and is a mastermind when it comes to mechanics. She created the DragonBall Radar. She later marries Vegeta in DBZ, and has a child named Trunks.
Cell: A very power villian who appears in DBZ, DBGT. He is the one who kills 16, triggering Gohan's transformation into SS2. His first form is more like a huge bug than a warrior, the second after absorbing 17, is more human like but looks like the Hulk, and his 3rd, is a human face after he absorbs 18, but is still eventually killed by one of Gohan's most powerful attacks.
Chouzu: A little guy all throughout the series and looks like a mime. He is somehow telepathically connected with his best friend Tien. He is never that strong.
Chi-Chi: Goku's wife. She is known for her bad temper and for her anormous fighting power. She hardly fights in the series.
Dende: He is a little green namek that Gohan and Krillin first meet on Planet Namek. He has the power to heal people and is used during the Frieza saga. He eventually becomes the new guardian of the earth.
Frieza: He is the main villian in the Namek saga which happens in DBZ. His father's name is King Cold. He also has a brother named Kooler, who was destroyed by Vegeta and Goku in Movie 6. When Freiza kills Goku's best friend Krillin, Goku turns into a SS and defeats Frieza. Then his father, gathers bits and pieces of him that are left and created a cybornetic creature called Cyborg Frieza. He is later killed by Future Trunks.
Ginyu Force: A member of 5 elite soilders (Recoom, Baata, Jiece, Captain Ginyu, and Guldo). They are all destroyed by the Z-team (Gohan, Goku, Vegeta, Krillin).
Gohan: He is Goku's son and has an extraodinary amount of hidden power which is released by the eldest Namek. His amazing power travels him through, DBZ, DBGT, where he turns SS in the room of spirit and time, and SS2, when Cell kills android 16. Although you predict him to become a great warrior in the following DBGT, it is a big dissapointment, as he turns out to be a low-class SuperHero (SaiyanMan), and a nerd.
Goku: He is the main character in DB, DBZ, DBGT. He was sent to Earth as a baby to conquer it, but bumped his head on a rock and lost his memory. He also, as his son has amazing powers, and turns SS at the death of his freind Krillin. He turns SS2, and SS3, while he is dead, and SS4 somewhere in GT, along the Super 17 era, and the Bebi era.
Gogeta: He is the fusion of Goku and Vegeta. He is the result of the fusion dance. He has the ability to turn SS, SS2, SS3, SS4. He is by far one of the most strongest warriors, but is not seen that much. He appears in his SS4 stage, in the Evil Shenlong era.
Goten: He is Goku's second son, and loves to fight. He is best freinds with Vegeta's son, Trunks, as they kill off Mutated Brolli. He turns SS at a very young age (9), and he turns into a lady's man in GT.
Gotenks: He is the result of the fusion dance between Goten and Trunks. He appears in the Majin Buu saga, but a huge dissapointment, not in GT. He has the ability to go SS3, only one of two people who obtained that level (the other being Goku).
Kammesennin Roshi: He is the martial arts instructor who taught Goku to become a great warrior. In the whole series, he is portrayed as a pervert. He drinks an immortality potion sometime in GT, or something like that.
Kami: He is the ruler of the earth. Somehow, he is connected to Piccolo, so if Piccolo dies or he dies, the other will fade off into another demension as well. He merges with Piccolo in the Android Saga, seeing the need for a boost in power level. Since he is gone, the DragonBalls dissapear, as if he were dead. So then, Dende comes, back, looking like Nail, and steps in as the new ruler of the earth.
King Cold: He is the father of Frieza. He is easily killed by Future Trunks.
King Kai: He is the little fat blue guy who lives on the little small planet Goku trains on before the Saiyan saga. He is the most corniest person on the show, as he has one condition for him to train you, you have to make him laugh!
Korin: He is the cat the lives in the heavens. He is the founder and maker of the Senzu Beans.
Krillin: He is the little munk who trains with Goku in the beginning of DBZ. He packs a bundle for a little guy, but never seems to keep up with everyone else. He wishes for hair in DBGT from the Dragon, but hardely appears in the series. The one thing that has puzzled me, is the 6 dots on his head.
MajinBuu, SuperBuu, KidBuu: They were created by an evil magician called Badibi. The Z warriors were warned about his arrival 10 years before he came. Sounds exactly like the Android saga if you ask me. Super Buu, the fat one, later merges with Ubuu to defeat Bebi. Kid Buu, is destroyed by Goku, and Majin Buu is the one who turns into KidBuu. KidBuu was a evil little kid thousands of years ago, that was a maniac, and killed millions, after containing him in a capsule, the evil magician Badibi released him. MajinBuu absorbs Gohan, and Gotenks, when he absorbs Gotenks he looks awsome!
Nappa: He was the acompany of Vegeta, when they came to earth, in the Saiyan Saga. He is killed by Vegeta because of his weakness shown against Goku, and later killed by Vegeta again in GT, when he arises from Hell.
Pan: She is the daughter of Videl and Gohan. She goes on a search with Goku, and Trunks in GT for the Ultimate DragonBalls.
Piccolo: He is the son of Piccolo Daimoah. When a namek named Piccolo wanted to become earth's guardian, he had to rid himself of evil. So he split in two. The evil side was killed by Goku, and the egg that the evil Piccolo shot out was what we now know as Piccolo (from this series). He has a hatred for Goku, but learns to enjoy life, after training Gohan, and being wished back in the Freiza saga, after his emotional death in the Saiyan saga by Nappa.
Tien: He is a deformed human with 3 eyes. Chouso and Tien are telepathically conncected. He helps a little in the Saiyan Saga, and probably the most in the Cell Saga. He is the winner of one of the Martial Arts Tournaments.
Future Trunks: He is the future version of the chibi Trunks we know from the Majin Buu Saga. He is incredibly strong, and warns Goku about the Androids. In his timeline, Goku has died of a heart disease, and all of the Z warriors have died from the Androids. He is all alone. He is the son of Vegeta. After his fight with Cell, he returns to his timeline and kills both of the Androids easily. Then, he probably lives in peace with his mother Bulma.
Trunks: He is the Trunks we know from the Majin Buu, and the Brolli Saga. He turns SS a year before Goten (8). Goten and Trunks have the ability to fuse into the powerful warrior Gotenks. He appears in GT, and turns out to be the Capsule Corperation owner.
Vegeta: He is the prince of all Saiyans. He has the ability to go SS, SS2, and SS4. His first appearence is in the saiyan saga, where he is defeated by Goku, Krillin, and Gohan. He follows them to Namek, where he joins forces with them, to defeat Frieza, and the Ginyu Force. In GT, his body is taken over by Bebi, and becomes incredibly strong from his zombie form, Bebi. He marries Bulma, and has a son named Trunks. Yamcha: He never is a major character in any of the series. He is not that strong and has a weird Blue cat called Puar that always follows him. Yamcha would have killed Chibi Goku back in DB, but Bulma woke up from sleeping, and stopped the fight. He later joins up with the team. He looks really cool in the Android Saga, but he still isn't very strong.