Like what has already been said, "whatever knife I have on me". Since I've never actually had to "survive" anything much more than a bit of tiredness on those uphill switchbacks <img src="/images/graemlins/blush.gif" alt="" /> , I can't say from realworld experience. I imagine I'd like my ColdSteel SRK the most in a real survival situation. That's obviously not an EDC item, and I'd only have it while hiking/backpacking. The knife on me all the time is my Spyderco Native (current EDC), so that's probably my most likely "survival knife".