Unlock Bulletproof Lara:
Press and hold LT, then press A, RT, Y, RT, X, LB

Unlock Unlimited Assault Rifle Ammo:
Press and hold LB, then press A, B, A, LT, X, Y

Unlock Unlimited Grenades:
Press and hold LB, then press LT, Y, RT, B, LT, X

Unlock Unlimited Shotgun Shells:
Press and hold LB, then press RT, B, X, LT, X, A

Unlock Unlimited SMG Ammo:
Press and hold LB, then press B, Y, LT, RT, A, B

Unlock One Shot Kill:
Press and hold LT, then press Y, A, Y, X, LB, B

Unlock No Textures Mode:
Press and hold LT, then press LB, A, B, A, Y, RT

Wield Excalibur:
Press and hold LT, then press Y, A, B, RT, Y, LT

Wield Soul Reaver:
Press and hold LB, then press A, RT, B, RT, LT, X

Drain Enemy Health:
Press and hold LT, then press X, B, A, LB, RT, Y