Sure, you're going to need canned food for when the Big One hits. Everybody knows that. "That Sarah Palin makes me want to stock up on canned food!" folks say. Or, "The way the market is going, I'm going to run out and buy canned food!" Canned food is important.
But don't forget the moist towelettes.
After you crawl out of your bunker and don some kind of bone headdress to make yourself warlord of the Mad-Max-style post-apocalyptic wasteland that used to be your neighborhood... things might get a little messy. You'll be thankful for a refreshing wipe around your face and hands. Whether you've just eaten a bucket of barbecue, or you've just killed the Johnsons next door for their last half gallon of gasoline and a jar of unlabeled pills... it's the little things that count.