*
I pondered this very question not long ago, and did some research into what I considered the best knife for that job. The consideration was; if I could have only one blade in a survival situation, what would it be? We all have different thoughts on the matter, of course, but for me I decided on the Becker BK2 Campanion. Here's why:
Blade length of a little over 5 inches, one quarter of an inch thick. This is a really stout blade that is heavy and sturdy enough for chopping and batonning, yet is short enough for other camp chores like making fuzz sticks, skinning game, and preparing food. It may not be the ideal size blade for any of those tasks, but it does all of them well enough.
Steel is 1095 CorVan. It may not be the perfect steel -- INFI is certainly tougher and more stain resistant -- but it's a very good steel that holds an edge well and is easy to sharpen.
The handles are the most comfortable of any I've ever held. Remember that this knife would be in your hand for much of the day performing all the tasks you require, from shelter making to food prep: handles are important. Also, in another month or so, Micarta scales will be available. The scales on the BK2 are simply changed with a hex wrench.
The sheath is very good. Not the best that it could be, but very good.
So for around $60 you can have a virtually indestructible survival knife shipped to your door that will meet all of my criteria for a one-knife survival scenario.
Those are my considered thoughts. I simply can't spend several hundred dollars on a knife for this scenario when a BK2 will fill the bill as well (for me).
* I actually posted this in another thread yesterday, but it fits here, too.