Need to unlock all of the characters in Street Fighter IV? Here is your strategy. Follow it wisely young one!

1. Select Arcade Mode, then adjust the settings as follows:
Difficulty - Easiest
Rounds(Best Of) - 1
Time Limit - 99

2. Select one of the characters below to unlock its attached new character:

Abel - Unlocks Fei Long
Chun Li - Unlocks Gen
Crimson Viper - Unlocks Cammy
M. Bison - Unlocks Rose
Ryu - Unlocks Sakura
Sakura - Unlocks Dan

Once you've unlocked these characters, you can then unlock Akuma, Gouken, and Seth. Here's how:

1. Select Arcade Mode, then adjust the settings as follows:
Difficulty - Easiest
Rounds(Best Of) - 1
Time Limit - 99

2. To fight and unlock Akuma, you must get a Perfect match. You cannot lose any matches or use a continue when you die, which should be easy with the Easiest setting. After you beat Seth Akuma will appear. Beat him to unlock him.

2b. To unlock Gouken, you must first unlock Akuma, then get a Perfect match and 3 Ultra Combo finishes. You cannot lose any matches or use a continue. After you beat Seth Gouken will appear. Beat him to unlock him.

2c. To unlock Seth, beat the game with all 24 characters.

Good luck!