CRKT NIRK Pocket Knife.
The high-carbon stainless steel blade is a utilitarian drop point shape with a deep belly, high hollow ground for easy cutting, and with a swedged top edge to aid penetration. It is a hefty 0.131" thick. The blade can be opened with either hand using the oval thumb hole.
The 5185 tactical model receives a black oxide non-reflective coating, and has a Combined Razor-Sharp & Triple-Point Serrated edge. The NIRK also comes with a stainless steel pocket/gear clip.
There you have it: a simple, flat, almost indestructible folder. All you need to do is oil and sharpen it occasionally and you have a friend for life. It is priced so you can afford several: one for the toolbox, one for the backpack, one for the truck, one for the boat, one for the survival kit.