Dragon Ball Z: Budokai 2

The first level pits you and your allies against Nappa, Vegeta, and a few Saibamen. The goal of the level is to get the Dragonball before Nappa does. Nappa will make a run for the Dragonball but is easy to intercept. Vegeta will summon Saibamen and attack you and your allies, and Saibamen will also attack you and your allies. The level does not end until either you or Nappa gets the Dragonball. Kill Nappa so he cannot get the Dragonball. Kill Vegeta so he cannot summon Saibamen or attack you. Kill all Saibamen so they also cannot attack you. Doing this guarantees victory, as Nappa is dead so nobody but you or your allies can get the dragonball. However because the level will not end until you get it, you can do whatever you want. When you are standing still, you can either move to another location on the level or search the area you are in. Your allies can also do this. You can search a location multiple times, which can garner money, capsules, items for battles, and even Dragonballs, but you will not always get something. Collecting the Dragonball will end the mission and you cannot repeat this again until you finish the story or restart the game. Moreover, this is the only mission where collecting a Dragonball is a requirement. Note: Fight Nappa with Krillen to hear funny banter between them.

Get a Viral Heart Disease Skill and put it on for support. Then, get a Vaccine to not make your Power decrease, but your opponent's will. Just block until their health is in the orange. You should now be able to defeat them.

When you initiate Burst mode in battle, instead of just randomly pressing buttons (as the game suggests), use the palm of your hand to rotate the Analog-stick and C-stick either clockwise or counter-clockwise, depending on which is more comfortable for you. Note: For optimal performance, use your dominant hand (if you are right-handed, use your right hand; and if left-handed, use your left).
C Bell.

Go to edit skills and choose any character. Then put Viral Heart Disease, Vaccine, and Senzu Bean. You will have one space remaining to put anything desired. If you die even if using Viral Heart Disease and Vaccine, you always have the Senzu Bean.
Fishingbaj.

When your opponent uses his special that does not need to be in contact with you (such as Destructo Disc), if you are far enough away you can press Down + A to dodge the attack, and then press Over + X to shoot your special, which almost always hits them.
Kurt Lehrke.

When fighting a short opponent, kick them into the air. You will be able hit and kick them as if you were fighting Cell or someone similar.
John Winters.

To defeat any villain easier (especially Fat Buu, Super Buu, and Kid Buu), choose any character and go to the skill sheet. Add some good Ki attacks then choose the Vital Heart Disease. The opponent's health will slowly decrease. The best partners against Kid Buu are Gohan and Trunks. Use Gohan until Kid Buu does not let up. On the last health block, use Trunks. Also, the character that defeats Kid Buu will receive the best attack one would need with that person.
Michael Boyd.

Frieza's Space Ship
Death Beam or Death Wave
Death Ball
Put anything in the last slot

At the end of Dragon World, defeat Kid Buu With the desired character to gain their devastation move. For example, Goku's Super Spirit Bomb, Vegeta's Big Bang Attack, Gohan's Super Kamehemehe, etc.

To get all Breakthrough Capsules, complete Advanced Tournament with a good character (to get all the good side breakthroughs), then complete it with an evil character to get theirs. Note: You may have to complete every tournament level with a good and an evil character.

Super Saiyan
Mix Blood Power
Z-Sword
Super Kami Water
Super Kamehameha x2
Note: For Teen Gohan replace Z-Sword with SS2.

Put the following in the capsule slots: Mysterious Vest, Saiyan Spirit, Ki Flash (optional), and Kamekameha (optional). You will not need to block because you will have 175% defense.

Note: This also works for Hercule. Put the following in the capsule slots: Saiyin Spirit (or Hercule's False Courage), Miracle Power (or Kings Confidence), and the Study Vest (World Champion Vest). If Super Buu gets the Tien and Yamcha Absorption, you will be invincible.

King Kai Fist x20
Super Saiyan
Warp Kamehameaha
Kamehameaha
Spirit Bomb
Continuous Kamehameaha
Meditation
(You should not have other levels of SS because they take up too much room)

Use the following setup. Charge until you have five full capsule charge things, then press K(2), Right, K(2), E. Try to rotate the Analog-stick and C-stick faster than your opponent and you will be Super Saiyan and deal 1,980 damage. If your opponent is still up, use Spirit Bomb (Left, P, P(2), K, E).
Martin Sweeny.

King Kai Fist x20
Super Saiyan
Super Spirit Ball
Super Spirit Ball
Spirit Ball
Spirit Ball
Kamehameha

Use the following setup. Start off with the basic P(4), E for Kamehameha. Double step backward, and the opponent will probably send a blast attack (Kamehameha, Galic Gun, etc.). Dodge it and use a plain Kamehameha attack. Now just use stronger punch attacks (Right, P(4); or Right, K(4); or P + K). Use this time to power-up to about four Ki levels and become Super Saiyan 2, and use the Warp Kamehameha attack. Then, power-up again and use that attack once more. If this did not finish them off, a few punches with a Kamehameha should do the trick.
Vidiogamer64.

King Kai Fist x20 (needed to turn Super Saiyan)
Super Saiyan
Super Saiyan 2 (boosts all attacks greatly)
Kamehameha (use when opponent's health is down or after dodging blast attack)
Warp Kamehameha
Warp Kamehameha
Angel's Halo (while in Super Saiyan 2, or King Kai Fist, Ki does not drop)

After defeating the Supreme Kai on the Supreme Kai planet, fight Vegeta and kill him to receive the Super Saiyan 2 capsule for Goku. You need four Ki bars to transform into Super Saiyan 2.

First get the Gokule capsule for either Goku or Hercule. Then, before selecting either character, first change the appearance to their alternate costume by pressing Up or Down. Next, select the character along with the capsule. When you use the fusion and it is successful, Gokule will appear differently. You can do with other fusions, but their costume will only change.