I think i'd have to say the standard AR-15 with telescoping stock and lots of ammo!
Another + for the ammo, ammo, ammo vote. I already have more guns than my household has hands, but more ammo, more MAGAZINES, and reloading components are vital.
Good luck the band is here and you can't find any thing good to buy. I have had AR's on back order for four months. My wholesalers are out of every thing. I am out of every thing. The auctions and the gun shows are the only place left. They will go away with the band too.
I like the idea of Ammo, but powder, primers bullets and brass are definitely in my future.
I have become more optimistic, and now believe that things could get worse.