My current faveorite is an A. T. Barr flat-ground liner lock (see pix 19 at http://www.customknives.com/fold6.htm. So, OK, it may not be perfect, but it's bead-blasted, so I'm not afraid to sharpen it, and it really feels good in the hand. It's large enough to do a good job on notching a 2X4, flat-cut for a good sweep draw-cut through a pasteboard box or canvas, holds an edge for a goodly time, and is pretty easy to sharpen with a Spyderco or EdgePro.
This is not the perfect knife - but it's the best I've found yet. I'm still looking.
------------------