Great posts - for me weapon and caliber are important.
I'd choose Glock 19 and AR-15 due to function and availability of ammo/spare parts. AK-47 makes lots of sense to me as well, but mine is chambered in .308 and it's quite heavy. Gotta figure on traveling light and fast.
No matter where I'm going - I have a nice little Kel-Tec SU-16b that folds up real nice to give me a bit of "reach out and touch" - but I agree, only leaving my residence if I had to go...
All the prepper stuff makes me smile - they even have prepper foods at Costco now.
All the food and water in the world won't matter if you have no way to defend yourself :).
Great answers! Interesting thoughts behind them as well. There really iis no "right" answer...

