Designate one shotgun, one rifle and one handgun as your primary "social unrest" home defense weapons and load up on the ammo for them. Having 20 guns doesn't do you any good if all you have is a few rounds for each. Kinda hard to watch out the FRONT living room window where the armed looters are moving around and dig through the BACK bedroom closet for more ammo. ("I KNOW I have at least a half box of .270 somewhere from last deer season......where the hell is it ???").
If you can't afford lots of expensive high caliber ammo, get a few bricks of .22 ammo. 300 rounds flying out that window from your .22 rifle and pistol may not drop a 250 lb man, but a wound in the arm with a .22 will slow him down, take him off the attack and put HIM on defense. Plus, with a bucket of .22 ammo, your wife and kid can easily load one gun while you shot the other.
Failed to mention magazines / clips. It's great that you have 1 EXTRA mag that came with your favorite deer rifle, B-U-T a total of 2 mags with only 5 rounds each isn't going to last long until you hear "click" and stop shooting to reload them. If you can't get oversize mags, get a sack full of the "regular" ones.
For urban environment, .22 is the chosen tool for operations by ex-spec-ops folk:
http://www.warriortalk.com/showthread.php?68441-My-GSR-decision....22lr.
Scope and fmj rounds for head shots and suppressed for non-telegraphing your whereabouts.
Homemade sound suppressors, explosives and other goodies can be found in manuals off www.scribd.com
Plenty of rifle magazines, happy sticks for pistols, celox, first aid, blades, blackjacks, water for moving and scooting away. Nothing carried should say “gun” like tactical pistol or rifle cases.
Pistols, supplies in messanger bag, tennis racket pouch (with balls), semi-auto rifle in guitar gig bag, machine pistol in gym bag with towel/running shoes, folded or stout carbines/machine pistols in attache case, cereal boxes lined with bubble wrap for pistols, ammo, carried in grocery bag.
I personally would like heavy caliber rifles like .338 Lapau or .50 BMG — not for long range sniping, but tactically close for defeating armor, taking out vehicles or helicopters. Perhaps if we get to that level — but why should I pay for it? Only just to get that cash from the assaulting tyrannical forces who have been funded by our tax dollars.
Obtaining hard cash for exploits is another issue that needs to be thought about.