How much ammo is a reasonable quantity to have on hand?

I'm NOT a "survivalist" in the Militia mode, nor a hunter. I live in a suburban/semi-rural area, not on a homestead or farm. But I do own rifles, shotguns and pistols. I think that makes me fairly typical of preparedness types.

I'm not worried about fighting off the Jack Booted Thugs of the New World Order or the Spiky Haired Mutants of Mad Max fame.

I would just like to protect me and mine from the type of criminal predators that already exist and might seize a moment of chaos to try to take advantage, or perhaps just from ordinary folks temporarily pushed over the edge by stress, fear and panic.

I would also like to be able to harvest whatever available animal protein that I can and be minimally prepared for an economic or societal "Nuclear Winter."

I know "more is better" and "you can never have enough," and I have my own ideas of minimum amounts to keep on hand, but I would like to hear yours.

What quantities of pistol, rifle and shotgun ammunition would advise someone new to survival preps to keep on hand, as a baseline?

Jeff