Krillin (Kuririn クリ リン) is Goku's best friend and a fighter-Z is short and bald (except for years later) and provides comic relief during tense moments. He is an artist debonair, outgoing and competitive martial. His only vice seems to be his genuine interest in women, although the series progresses, his intentions lean more romantic, and dangerous situations, he despairs sometimes death may be single. Once a fierce rival of Goku, he quickly became her best friend while training of Master Roshi. It is also close to the son of Goku, Gohan. He eventually marries Android 18 and moved to have a daughter named Marron. Krillin is known to be very clever for his fights often based on encouraging opponents to defeat them ....
Yamcha (ヤムチャ Yamucha) is a former desert bandit. There was once an enemy of Goku, but eventually reformed and became a friend and ally. It was the first of the Z fighters possible to meet and team up with Goku. It was once the boyfriend of Bulma, and is a constant companion Puar. His name is a play of "yum cha" (literally "tea"), referring to a gathering to drink tea and eat dim sum.    It has the distinction of being one Z Fighter Goku had the longest, even longer than Krillin.
Tien ShinHan (Tien)
Tien Shinhan (天津 饭 Tenshinhan) (generally referred to simply as Tien in the English dub) is a man introduced towards the end of the Fortuneteller Baba saga in the anime. Because of his strict upbringing, he is first cold and no heart, thinking of nothing exploitation of innocent and inflict pain. However, Roshi and Goku eventually help him see the folly of the teachings of his master, and he becomes a trusted ally. He went on to fight as Fighter Z, but withdrew after the fight against it is no longer able to compete with the power of Super Saiyan.
Chiaotzu (饺子 Chaozu) is a white skin, red-cheeked man who is constant companions with Tien Shinhan, his best friend. Like Krillin, Chiaotzu has no visible nose. He is first introduced late in the Fortuneteller Baba saga in the anime. At the time he was studying Crane School, he formed a rivalry with Turtle School student for a while Krillin in the 22nd World Martial Arts Tournament. With Tien, it moves quickly along after seeing the folly of the teachings of his master, and becomes a trusted ally and Z Fighter. It is fairly quiet, but brave psychic martial artist who is willing to help his friends whenever possible and is very dedicated to his training with Tien.
Bulma (ブルマ, Buruma) is the daughter of the founder of Capsule Corporation, Dr. Brief and is the first friend of Goku. She used to be the girlfriend of Yamcha, but moved on, and became the wife of Vegeta. With him she had a son named Trunks and a daughter named Bulla. She lives in the west of the city all his life, and her address is listed as WST 3338926 K.
Apart from Goku, Bulma is the only character the oldest in the meta-set of the series, being introduced only a few minutes after Goku in the first episode of Dragon Ball, "The Secret of the Dragon Balls" And lasting until the final episode of Dragon Ball GT "Until We Meet Again".
This article is inspired from the Dragonball Wikia which can be found here: http://dragonball.wikia.com/wiki/Main_Page