Dragon Ball Z

Son Goku: who trains in the Other World with King Kai to return in time and save his friends.
Piccolo: He trains young Gohan for a year to prepare him for battle, putting aside his old rivalry with Goku.
Son Gohan: Goku's son, who despite his young age and inexperience, demonstrates a giant hidden power.
Krillin: Goku's best friend, who leads the defense on Earth while Goku is on his way. Yamcha, Tien Shinhan, and Chiaotzu: Skilled warriors who join the defense and train hard at Kami's Lookout.
Yajirobe: Although he is often not counted on the front line of battle, he was pivotal with his sword at the end of the conflict.
Kamisama: The god of the Earth, who allows warriors to train in his palace and assists from the sky.
USER: He is a Saiyan who was sent to Earth and fell into Bulma's house and grew up with her. They are also husband and wife before the martial arts tournament where Goku married Chi-Chi.

Raditz: Goku's older brother, who travels to Earth to recruit him and annihilate humanity.
Nappa: A ruthless and burly giant who accompanies Vegeta as his right-hand man and subordinate.
Vegeta: The Prince of the Saiyans and main antagonist of the saga, who comes to Earth motivated by the desire to obtain the Dragon Balls to gain immortality.
Quick summary :
Raditz → Nappa → Vegeta → Final fight Goku vs Vegeta.

1. Frieza's army

• Frieza : The main villain of the saga. Emperor of the universe, genocidal maniac of the Saiyans. He has 4 transformations and is super sadistic.
• Zarbon : Frieza's "handsome" one. Elegant but transforms into a monster. Frieza's right-hand man on Namek.
• Dodoria : Frieza's other general. Brutish, loyal, and the one who told Vegeta the truth about the destruction of Planet Vegeta.
• Ginyu Special Forces / Ginyu Tokusentai
• Captain Ginyu : The leader. He can change bodies with his "Change" technique.
• Recoome : The muscular guy who laughs out loud.
• Burter : "The fastest in the universe."
• Jeice : The redhead with the fiery hairstyle. Burter's best friend.
• Guldo : The little boy with psychic powers to stop time.

2. Other villains/antagonists

• Kiwui : One of Frieza's elite soldiers. Vegeta kills him as soon as he arrives on Namek to show off his new power.
• Appule, Orlen, Rasin : Low-ranking soldiers who appear guarding the ships.

The most iconic fight order :
Kiwui → Dodoria → Zarbon → Ginyu Force → Frieza.

1. Dr. Gero's Androids
Dr. Gero created them to get revenge on Goku.

• Android 19 : The fat one who absorbs energy. Vegeta kills him.
• Android 20 / Dr. Gero : The creator of them all. He is killed by Androids 17 and 18.
• Android 16 : Pacifist, only wants to kill Goku. He is destroyed by Cell.
• Android 17 : Rebellious and overconfident. Cell absorbs him to reach his perfect form.
• Android 18 : 17's sister. She is also absorbed by Cell. Later she marries Krillin.

2. Cell
The main villain of the saga.
It is a bio-android created with cells from Goku, Vegeta, Piccolo, Frieza and more.
His goal: to absorb Androids 17 and 18 to reach his "Perfect Form".
It has 3 forms: Imperfect → Semi-Perfect → Perfect.
He organizes the "Cell Games" and fights against Gohan SSJ2.

Order of villains :
Dr. Gero and 19 → 17 and 18 → Imperfect Cell → Perfect Cell

The Z Warriors

• Goku : Returns from the Other World. He reaches SSJ3 and teaches Goten and Trunks the Fusion technique.
• Vegeta : He allows himself to be controlled by Babidi to fight Goku. He sacrifices himself against Fat Buu.
• Gohan : He is given mystical power by Old Kai. He becomes the strongest for a while.
• Goten and Trunks : They learn Fusion and become Gotenks.
• Piccolo : Trains Goten and Trunks. He is absorbed by Super Buu.
• Krillin, Tien Shinhan, Yamcha : They provide support from behind.

Other allies

• Mr. Satan : The hero of Earth. He is the only one who manages to calm Fat Buu and save the world with his charisma.
• Videl : Help Satan and support Gohan.
• Kaio Shin and Kibito : The gods who warn about Buu.
• Dende : He becomes the new Kami of Earth.

Key fact of the saga
Many allies end up being absorbed: Gotenks, Piccolo, and Gohan fall into Super Buu.
And the greatest ally in the end is Satan, because without him Goku wouldn't have been able to create the Spirit Bomb against Kid Buu.

MAIN VILLAINS *

• 1. Babidi and his henchmen *
     -* Babidi : The wizard who awakens Majin Buu. He manipulates people with his magic.
     - Dabura : The king of the Demon Realm. Babidi's right-hand man. He turns people to stone.
     - Spopovich and Yamu : Humans possessed by Babidi. They steal energy from Gohan.
     - Pui Pui, Yakon, etc *.: Warriors that Babidi uses to gain energy.
• 2. Majin Buu *
     He has several forms, and all of them are a problem:
     -* Fat Majin Buu : Childish, gluttonous, and destructive. He becomes friends with Satan. - Evil Buu : Born when Fat Buu expels all his evil. - Super Buu : Absorbs Gotenks and Piccolo. The most intelligent and dangerous. - Kid Buu : The pure and original form. He only wants to destroy. He is the one Goku SSJ3 fights against. Order: Babidi/Dabura → Fat Buu → Super Buu → Kid Buu