I am a bit of a Spyderco fan. I have a Spyderco Salt II in my pocket right now, but that might be a little small or light for the kinds of things you're talking about. The Spyderco Manix, which I have used but do not own, seems to be a very good knife indeed.

I personally put a Becker Necker in my larger survival kit instead of a folder. It's no longer in production and prices are climbing as a result, but it is small, light, extremely sturdy, and holds a very good edge. It has some additional functions - the handle has a cap lifter and a wire breaking notch in the butt. The skeleton handle also makes it easy to lash it to a pole for use as a spear.