A traditional gardening tool of Japan, my hori hori is the number two tool that I always carry when harvesting and working in the garden (second only to my forged hand pruners). Use it for digging roots (great for dandelion), cutting handfuls of greens, or sawing thick plant stems off at ground level when doing garden cleanup.
This is not the exact hori hori I own (I have two others), but this is the one I would buy if I got another. You want to make sure whichever hori hori you choose comes with a holster for easy carrying. I like that this one comes with a sharpening tool that likely could also be used for your hand pruners as well.