Some great posts guys with very useful info. I have a bug-out/bug-in/survival back pack. It's an internal frame pack, you name it, it's probably in there. It's weighs about 40lbs., but for me, that's grab and go. I've also got my gun bag ready to go, ammo, reloading supplies, and gun kit. Here's some things I find essential to have: Short term water(survival water packs), Long term water(micron filter, purification tablets), Short term rations(MRE's, freeze dried, protein bars), Long term food gathering(snare kit, snare instructions), Fire Kit( Magnesium starter, blast match, flint and steel, 9 volt battery w/ steel wool, tinder), First aid kit, Good sharp knife and several other knives, small mess kit, Emergency blanket, zip-loc bags, rope/para-cord, whistle, compass, signaling mirror, solar/crank emergency radio, change of clothes, and two books: a survival book( US Army, SAS or similar book), and My personal choice: A Bible. The most important things you can have in a survival situation can't be put in the bag, 1: A positive attitude and outlook ( Having confidence you're going to survive and looking forward to better times)
2: Survival Instinct (Recognize what has to be done, make the right decision, and do it.) 3: Knowledge ( Sure, you can rely on a survival manual, but having those knowledge and skills in your own "memory banks" before you need them is so much better.)