Always Three
I always have three knives on my person.
If I were to go camping, I might change one or add one.
Daily, I have a small pocket knife in the two-inch range (usually Gerber Silver Knight, 1982), a multi-tool of some kind (usually Leatherman, Supertool 1998-ish or Wave 2002-ish), and something in a three-inch folder (usually Kershaw Leek, 2006). In years past, my "multi-tool" was a SAK patterned Imperial.
In the woods, I would probably change out the Leek for a heavier knife, like the Kershaw 3120 or 3140, or alternatively a Buck 112 or 110 (size and shape: K3120 = B112, K3140 = B110). And just to confuse things, I've recently been testing a large sodbuster; very useful indeed, and every bit as large as a Buck 110 -- just lighter.
I would add a fixed blade. If weight was an issue, the fixed blade would replace the larger folder. Current favorite is a four-inch Marttiini MN15 field knife. Anything larger would stay in the car, although I could be tempted to carry a light hatchet, depending on circumstances.
When I was much younger, I hiked with a USMC bolo (short machete) and the SAK-style Imperial. Dragging that bolo around up and down hills is a young man's game. I wouldn't do that now. There's a little Canadian hatchet that goes on the belt, weighs less than 20 oz, I think. I might carry that.
I carry the Leek as EDC because it's light and flat. I wouldn't expect it to take serious punishment like, say, a Buck 110/112 or the Kershaw 3140/3120 so, in the woods, light-and-flat gets to stay home.
The Silver Knight has been with me more than 25 years, and it does what I need it to, so I'm quite comfortable with it. I could arguably replace it with a small sodbuster in yonder woods, but I think there's something to be said for having a tool that knows your hand, though it be less than "ideal" for the task.
The Marttiini is right up there with various Mora (Swedish) knives. I would be completely comfortable with the MN15 or MN10 or any of the Current production Mora knives, like the Mora 2000, Clipper, or Frost's Swedish Army knife. They're all light, robust, sharp, and well-fitted to the hand.
The sad thing about having a wide selection of cutlery is having to choose two or three from dozens of equally qualified pieces. I've chosen the Marttiini/Mora pattern over the Buck 119, but the Buck is a great knife, quite suitable to the job.
I chose the Leatherman over a SAK-style knife because, hey, you never know when you'll need pliers, right? And yet, that SAK pattern has spent way more time in the woods with me than the Leatherman.
I've recently been carrying an old (rescued) Uncle Henry stockman pattern just to get the feel of it. Damned handy little thing.
Basically, for any outing, there will be a little folder (2-ish inches), a bigger folder (3-4 inches), a multi-tool, and a fixed blade (3.5-5 inches). If weight's a problem I'd have to choose between the larger folder and the fixed blade.
What I REALLY need is Heinlein's "fold box" from Glory Road. Then I can bring my whole collection, and weight be damned.
*Sigh*
Sometimes it sux being a geek.
