It would depend on time. My 1911 is my quick-access firearm. My trusty target .357 is 10 minutes to get to.
If I had to run, it will be a 1911 commander size, a shield 9, and a .308 Scout. With a small ammo box of those calibers (yes, the mags are all loaded so range trips are easy to pull off). Three minutes extra, the Ruger .22 gets added.
But I would have to say that for me, to leave my small corner of the world, where we all look out for each other, and go out in the wild that my part of town would become, does not make sense. If I can't see a mushroom cloud, I'm sitting tight. I'm an old dead guy anyway, have to protect the young folks as I can.
So I'd say a trusted handgun and a good, easy to carry, rifle.