Android 20:
Defeat Android 20 with Goku.

Android 18:
Defeat Android 18 with Krillen.

Android 17:
Defeat Android 17 with Piccolo.

Android 16:
Defeat Android 16 with Goku.

Super Saiyan 2 (Vegeta):
Defeat Super Buu (Gohan) as Vegeto Stage 8

Super Saiyan 2 (Goku):
Defeat Cell on stage 4 with Goku

Super Saiyan (Goku):
Let Krillen die on Stage 3.

Super Saiyan 3 (Goku):
Defeat Majin(Fat) Buu on stage 6 with Goku

Teen Gohan:
Defeat Cell for the last time on Supreme Kai's planet with Adult Gohan.

Supreme Kai:
Defeat Supreme Kai with Goku.

Vegeta:
Defeat Vegeta with Goku on Namek.

Tiencha (Capsule):
Get both Breakthoughs of Tien and Yamcha

Vegeto (Capsule/Vegeta):
Wish for it on the Dragonballs

Vegeto (Capsule/Goku):
Get Goku to Surpreme Ki then to Vegeta Stage 8

Yamcha:
Defeat Nappa with Tien.

Videl:
Defeat Super Buu (Gohan) as Hercule Stage 8

SSJ2 Gohan (adult):
Defeat Majin Vegeta before Majin Buu kills Babidi in Stage 6 (the area with the large ring)

Silver Membership Card:
Have a Budokai 1 save on your memory card when you start a New Game

Saiyaman:
Defeat Cell with Gohan (adult) only.

Recoome:
Defeat Recoome with Goku.

Nappa:
Defeat Nappa with Vegeta (can only be done when you unlock Vegeta and start Dragon mode again).

Majin Vegeta:
Dragon World, Stage 5. Defeat any Majin character to get the Capsule that allows you to get Majin Vegeta. Dabura does not count.

Kabitoki (Capsule):
Wish for it on the Dragonballs.

Kabitoshin (Potara):
Collect seven dragonballs and wish for the capsule from the Dragon.

Hercule:
Defeat Fat Buu with Great Saiyaman stage 6.

Gokule (capsule):
Get Goku and hercule's breakthrough.

Gotenks (Capsule):
Once enteared stage 7 it's yours.

Ginyu:
Defeat Ginyu on Namek with Vegeta.

Frieza:
Defeat Frieza with Goku.

Future Trunks:
Defeat Vegeta on Namek with Kid Trunks.

Dabura:
Get 100 Kili on Babidi's Spaceship.

City Street Stage:
Defeat super Buu with Gohan on stage 8 without being defeated.

Cell:
Defeat Cell with Goku.

Breakthroughs:
Wish for them with the Dragonballs.

Bulma's costumes2--6:
Wish for them on the Dragonballs.

Babidi's Ship:
Collect All 7 Dragon Balls and Wish for it from Shenron.

Babidi's Spaceship:
Wish for it on the Dragonballs.

Advanced World Tournament:
Unlock all 29 Characters, then buy it from Bulma.

Adept World Tournament:
Unlock 16 Characters, then buy it from Bulma.

Cell Games Rules:
Come in 1st in the World Tournament: Advanced Mode

First Level Transformation Capsule (except Goku):
Defeat Frieza on stage 3 with that character.

Unlock Potential (Krillin):
On stage 3 go to the spot on the right of the farthest spot in the upper left with a ki down symbol.

Present For You (Hercule):
Defeat Super Buu on stage 8 with Hercule before Gohan absorption.

Fierce Destructo Disc (Krillin):
Defeat Super Buu on stage 8 or Kid Buu on stage 9 with Krillin.

Hercule Special (Hercule):
Defeat Kid Buu on stage 9 with Hercule.

Big Bang Attack (Vegeta):
Defeat Kid Buu on stage 9 with Vegeta.

Hellzone Grenade (Piccolo):
Defeat Kid Buu on stage 9 with Piccolo.

Bibidi's Guard:
Get 8000 kili in Babidi's Spaceship
Warp Kamehameha (Kid Buu) Get 8660 kili in Babidi's Spaceship.

Z-Sword On stage 9:
go towards the hidden spot behind the mountain with the Z-Sword

Korin's Teachings:
Complete Master Roshi's Teachings.

Kami's Teachings:
Complete Korin's Teachings.

King Kai's Teachings:
Complete Kami's Teachings.

Elder Kai's Teachings:
Complete King Kai's Teachings.

Goku's Teachings:
CompleteElder Kai's Teachings.

Demonic Will (Dabura):
Collect 540 kili in Babidi's Spaceship.

Hell Blade Rush (Dabura):
Collect 4040 kili in Babidi's Spaceship.

Loyalty to Babidi (Dabura):
Collect 4975 kili in Babidi's Spaceship.

Angry Explosion (Majin Buu):
Collect 6185 kili in Babidi's Spaceship.

Dabura Cookie:
Collect 6790 kili in Babidi's Spaceship.

Human Candy:
Collect 7175 kili in Babidi's Spaceship.

Toxic Chocolate:
Collect 7505 kili in Babidi's Spaceship.

Z Difficulty:
Complete Dragon World on Very Hard.

Z2 Difficulty:
Complete Dragon World on Z.

Senzu Bean:
Dig twice on the spot where Kid Buu starts off on stage 9