The other answer you'll get is "the one you have with you".

The idea there is that it doesn't matter what kind of knife it is if it isn't with you when you find yourself "surviving".

If you read Doug Ritter's Bonus Survival Information that come with the Pocket Survival Pack, you will note that Doug recommends "A well-built, trustworthy folding (pocket) knife with a locking plade fore safety at least 2.5 inches in length" and "one-hand opening". While larger fixed blade knives are certainly more preferable, the point is that a good small folding knife in the hand is worth two in the bush (so to speak).

I myself carry a Leatherman Micra in my pocket, and ...

...when in the office a rittergrip in a "manbag"

...when in the field a rittergrip in a sheath on my belt and a Becker Crewman and/or Leatherman Charge Ti in my fannypack or daypack. When out with Scouts the Crewman has to stay home though.

By the way, the Becker Crewman is a much better slicer than the Brute, though it is still a pretty beefy knife.