First thought was Delica, but I think I'd go with PM2 S110V instead. Good corrosion resistance, lasting edge, tough build, solid lock, easy to maintain... I find that, while I prefer carrying something smaller in urban settings (manbug, delica, etc.), I don't depend on such blades as much as I do on the larger ones.
Put another way, a large blade can do what a smaller one does, but the opposite isn't always true.
The problem of a coherent civilization is the problem of living with ignorance and not being frustrated by it.