I'm pretty late getting to this thread, but...
My last rifle purchase took this very scenario in to consideration. It is a 16" AR carbine, heavy BBL, collapsable stock, flat top with a red dot reflex sight (soon to have fold down irons, too). I'd muster as many magazines as possible. Sidearm would be either my Sig 226 in .40 or my XD in .45.
My other consideration was my location in the world: Florida. If hurricane Katrina part II decided Florida is the place it wants to demolish, I wanted a light, maneuverable urban weapon with a lot of intimidation factor as well as wound capability out to 300 yards to protect my property/persons/neighborhood from looters and other wrong doers.
The AR fits that bill sportingly.