Dragon Ball Z: Budokai 2

To get Bulma's costumes, get all the Dragon Balls. Then, summon the dragon. If you are lucky, you can get Bulma's costumes. Bulma's costume will change the way that Bulma appears in the capsule shop.

Helicopter: Press Right, P(4), Left, P. Note: For Kid Buu press P(4), Left, P.
Funny long-arm: Press P, Right, P(2).
Fast-punch: Press P, K.
Hugging move: Press Right, P, K(3) as Super Buu.
Sitting: Press Right, K(2), Right, K(2).

Kamehamaha
Energy Field
Spirit Bomb
Cybernetic Radar/ Any other capsule
Lasso
Essence of the Mighty

Hold A when charging up for a special to charge faster. This the only way to get Majin Vegeta's Final Explosion move without getting destroyed.

When on Stage 2 on Babidi's ship, you can still customize your character. Before you continue with Stage 2, add a full Senzu Bean onto you customized character. After your one bar of life is gone you will use the Senzu Bean and regain three full bars of life, extending the time that you can "endure your opponent's attacks".

Turn you controller vertically and place your hand over the Analog-stick and C-stick. Rotate them both with your hand.

To defeat Buu easily in story mode, use Custom Goku with the following capsules:

20x King Kai Fist
Super Saiyan
Super Saiyan 2
Kamehameha
Vaccine
Viral Heart Disease

Use your allies to run own Buu's health. Recommended allies are Piccolo and Vegeta (Galick Gun, S.S. 1 and 2, Meteor Break, Meteor Flash).

Play as Goten or Kid Trunks. Have them be Super Saiyan and have two capsules of Kamehameha or Buster Cannon. Also get a quick fire type move such as Continuous Kamehameha (if Trunks has one). This works well because if you are tall (like Goku), you will kick over Buu's head.

When fighting Kid Buu for the final time, first destroy everything outside of his little place. Then, move your character and your allies all in the place and gang up on him.
KDKRE0L.

Select Goten and Gohan as your partners. Have Gohan go to Goten. This will give Goten 20 defensive points. Then, make Goku go to Goten. This will give Goten 30 defensive power-ups (160 defensive points). Then, go to the carpet that Mr.Popo has close to where you start. Go to Kid Buu and fight him with Goten. Make sure you have Super Saiyan and block frequently.
Aaron Sidhu.

Android 16: Hell Flash
Android 17: Power Falling Star
Android 18: Power Falling Star
Cell: Spirit Bomb
Dabura: Hell Blade Rush
Dr. Gero: Life Drain
Frieza: Death Ball
Ginyu: Body Change
Goku: Super Spirit Bomb
Gokule: Ultra Spirit Bomb
Goten: Continuous Kamehameha
Gotenks: Galactica Donuts and Super Kamikaze Ghost Attack
Great Saiyaman: Justice Carnival
Hercule: Hercule Speical
Kibitoshin: Majestic Rush
Kid Buu: Warp Kamehameha
Kid Trunks: Energy Burst
Krillin: Fierce Destructo Disc
Majin Buu: Angry Explosion
Mystic Gohan: Super Dragon Fist
Nappa: Breakstorm
Piccolo: Special Beam Cannon
Raditz: Weekly Special
Recoome: Recoome Bomber
Super Buu: Absorption
Supreme Kai: Majestic Rush
Teen Gohan: Fatherson Kamehameha
Teen Trunks: Burning Slash
Tien: Volleyball Fist
Tiencha: Wolf Fang Volleyball Fist
Trunks: Burning Slash
Vegeta: Big Bang Attack
Vegito: Spirit Sword
Videl: Videls Close Call
Yamacha: Wolf Fang Blast

To do those hard moves (for example, Burning Slash), input the moves without pushing all the arrows (for example, K, K, hold Right, K, K, P).
Gogetenks.

Equip two of the same type of beam attacks (such as Galick Gun, Kamehameha, Buster Cannon, etc.) to your fighter. They will be twice as big and powerful as before.