Doom 3

Skip checkpoints:
Hold L and press B, A, X, Y during game play to advance to the next
checkpoint. A sound will confirm correct code entry.

Invincibility:
Hold L and press X, Y, B, A during game play. A sound will confirm
correct code entry.

Doom Ultimate and Doom 2 Cheats: (Collector's Edition only)

Toggle God and Degreelessness mode:
Hold L and press A(4).

All weapons, ammunition, and armor:
Hold L and press B(4).

All weapons, health, keys, and armor:
Hold L and press A, B, A, B.

Temporary invincibility:
Hold L and press X(4).

Full map:
Hold L and press Y(4).

Berserk mode:
Hold L and press X(3), Y.

End level:
Hold L and press A(2), B(2).

Chainsaw:
Hold L and press B(2), A(2).

Invisibility:
Hold L and press X(2), Y(2).

Light Amplification Goggles:
Hold L and press Y(3), X.

Radiation Suit:
Hold L and press X, Y(3).

Walk through walls:
Hold L and press A, B, Y, X.