Hand guns, couple boxes of ammo, firebox with birth certs, passports, etc., change of clothes, water, $500 cash, $1000 in gold, and all the jewelry I can cram in the backpack. Food as able. Other items and the relative amounts would change depending on the precise evac reason and means of transportation, but this is my general "ready to go in 10 minutes" backpack, all purpose scenario. Except for zombies. Then, we go heavier on ammo, food, and baseball bats.
I had never really thought of this until we were put under "suggested mandatory evacuation" orders while I was in Corpus for Advanced. It's amazing what stuff you can instantly say "leave it" to when you're staring down the face of a natural disaster. Likewise, the kind of stuff you realize you want but don't have when the time comes ("Which car are we taking? Yours. Mine only has 1/3 tank of gas. Well mine only has 1/4. . .; or "They're saying on the news that all the ATMs are out of money and if this thing is big enough credit cards don't work." It's okay I just got money a few days ago; I have . . .crap. . . $36 and a receipt from the O'Club.).