Folders, as long as you don't count kitchen knives, which I don't. Almost all of us spend more time around people than we do in the woods, and you get a lot fewer hassles with folders. When I am going to need a fixed blade, I pull one out of the drawer and thread it on my belt. With folders, there's always a small one in my pocket, and others clipped to each of my outside coats.
I also note that my fixed blades follow a pattern. All but a couple have blades around 4" with drop or slight clip points. I could get along with just one, and did for many years. That pattern is far more useful to me than anything more specialized.
My folders are all over the place. Sometimes I want a small folder, sometimes a large. Sometimes a plain, and sometimes a dressy one. If I had to, I could skip the fixed blades and get by with one of large locking folders. Hadn't thought about this before, but my large locking folders are quite similar to my fixed blades.