There are several bonus characters you can unlock in Dragon Ball Z: Ultimate Tenkaichi for the PS3 and Xbox 360.
Here are the bonus characters you can unlock, and what must be done to unlock them.
Bardock – Defeat Bardock with Frieza in Story mode
Captain Ginyu – Defeat Captain Ginyu in Story mode
Cell – Defeat Cell with SSJ2 Gohan in Story mode
Raditz – Defeat Raditz with Goku and Piccolo in Story mode
Trunks – Defeat Goku with Trunks at the beginning of the Android Saga in Story mode
