Star Wars Battlefront II - PS2

Invincibility:
Pause game play in single player mode then press Up, Up, Up, Left, Down, Down, Down, Left, Up, Up, Up, Left, Right.

Unlimited ammunition:
Pause game play in single player mode then press Up, Down, Left, Down, Down, Left, Down, Down, Left, Down, Down, Down, Left, Right.

Low resolution soldiers:
Pause game play in single player mode then press Down, Down, Down, Up, Up, Left, Down, Down, Left, Up, Up, Up, Left.

Disable HUD:
Pause game play in single player or multi-player mode then press Up, Up, Up, Up, Left, Up, Up, Down, Left, Down, Up, Up, Left, Right.

Slow motion sounds:
Pause game play in single player mode then press Up, Up, Up, Left, Up, Down, Up, Up, Left, Down, Down, Down, Left, Up, Down, Down, Left, Right.

Party-time Jedi/Wampa hit effects:
Pause game play in single player mode then press Up, Down, Left, Down, Left, Right.

Unlimited Force Choke/Lightning:
You must be Vader, Dooku, Sidious or Anakin for this to work because it's very evil. Go ahead and start force choking some poor fool, and while holding the 'use force' button, switch force powers. Keep the 'use' button held, and you should keep them choking while your force meter fills up. Or, with them suspended helplessly, use force lightning on them at the same time. Now that's the dark side.