I don't use a bread machine to make bread, but I've had good luck using whole wheat pastry flour instead of regular flour. It's counter-intuitive, but it seems to make a lighter product. Another type of flour that works well is white flour with the germ added back. I guess they separate the bran and germ and only add the germ back. So it's halfway between white and whole wheat. I get it from my local co-op and I really like it, it's my flour of choice now.