Extra Characters Cheat :
To get the following extra characters, you have to beat original mode the following times with any character without using continues. A new character will appear after each completion.

Sagat - Once
Vega - Twice
Garuda - Three times
Shadow Geist - Four times
Kairi - Five times
Pullum - Six times
Area - Seven times
Darun - Eight times
Vulcano - Nine times

M Bison 2 : [Submitted by: Perfectopnoy]
Beat original mode with M Bison eight times, then go to the character select screen, highlight M Bison, press select and Cross.

Evil Ryu: [Submitted by: ]
Defeat the game 8x with Ryu. After that to select Evil Ryu, highlight Ryu and Hold Select, and press X, triangle, and Square.