I have and use all sorts of tools...hand tools, power tools, commercial tools, home made tools. I have way more tools than I really need because I like to try all sorts of techniques I learn from others (many of them here on ALR) and I go out and get the same tools others use. Some of these experiments work out for me and others don't, but I never get rid of a tool, even if I don't use it very often. It might come in handy later for something.
All that being said, the tool I absolutely love and use the most for stock shaping is a little junky tool that came in a set of Xacto knives I bought as a boy almost 50 years ago. It is a very cheaply made, die cast frame, miniature spoke shave.
I also, of course, use a much larger Stanley spoke shave and all the rasps, files, scrapers, planes, gouges, etc., mentioned by all the others here, but I use this little spoke shave more than anything else, hands down. It fits in tight places, takes off wood as fast or as slow as I like, and leaves a very nice surface. And, if the blade is sharpened correctly, it will cut with, across, or against the grain with equal ease. Since I don't like cheaply made tools, I have often contemplated making a much nicer version just this size out of steel or brass or ? but have never gotten around to it. This crazy little thing just works great and there is no sense messing with success.