As has been said, wood is wood, and it all burns, but there are differing elements to getting the most bang for your buck. I hate having to clean out my stove, so I go for woods that leave little ash. Sycamore seems to leave more ash than there was wood to begin with. Also it's hard to split and doesn't give off much heat, so I'll never burn it again. Other softwoods don't seem worth the trouble either, but for some of us, it's better than nothing. For those of us who have access to good wood, we can afford to be picky. Check out the sticky thread at the top of the page under "The Ultimate BTU Reference." That'll be of some help, but there are other factors in making a wood desirable than just BTU's. How well does it split, how much spark and pop does it give off, how much smoke, and how much ash left over.