If we focus on a non apocalyptic scene, gold works. With the devalue of other forms of curreny, gold will always hold value in a civilized society. Paper can get to be literally worthless if government continues on its path. This is what i assumed the OP was asking.
If it goes tho sh!t, buy ammo with your gold if you can time it right. Guns and ammo will get you very far in survival mode.