Have to agree, free is good. But if I have my choice I would have to say Red Oak and White Ash get my vote. Day in and Day out seasoned Red Oak is hard to beat. Puts out very good heat, lasts as long as I need it too and usually splits well when green and straight grained. I love all the oaks, pin/black, white, and chestnut. Downside is a long seasoning time and its pretty heavy when it is green. Love White Ash, splits like a dream, burns pretty dog gone well and dries fast. I have access to a lot of hickory and it burns great but the mess from all the borers and the fact that its so stringy to split at times puts it down on my list a little. But I love having a little for those really cold nights. Heck, I burn it all, love locust when I can get it, have access to a lot of small to medium dead elm, black birch is another good one for me that I will take all I can get. PA is blessed with a lot of great hardwoods, we are fortunate. I even like a little red maple in the rotation for those mild days. I will say I do not like poplar, heavy when green but dries out to feel like a feather, burns up too quick in my stove, I'd be out there feeding the fire every few hours with that stuff. Always keep a little pine, hemlock or cedar around for kindling. But day in and day out in the heart of winter give me seasoned OAK and I will be very happy.