I used to agree with Deb: my "sharpshooter" drain spade. Besides digging and turning and making ditches, it was a "reaching tool" that let me transplant into the middle of a bed without stepping on it, or near the edges without stooping over. I could cut seed furrows with it, or smooth down and firm a seed bed.
But since I bought a 4-tine cultivator, I think that's may new favorite. It tills, weeds, picks coarse stuff out of the compost heap's surface layer, picks up brush, and mixes soil amendments.