The first book I reviewed on the subject of "church history" was Diana Butler Bass' A People's History of Christianity: The Other Side of the Story. I didn't realize back then how much this book would shift my thinking. I believe it may have been my first encounter with "history from below" (the author follows Howard Zinn's historiography). When I wrote my review on August 27th, 2009, I said this, "If you or someone you know dismisses Christianity because of the crusades, or the inquisition, or bad popes, this may be a book that should be read." That said, I also expressed some concern with her entertainment of ideas deemed "heretical".
Today, though I haven't read this book in almost seven years, I'd say I stand by my recommendation and I'm a whole lot less concerned about the orthodoxy-heresy binary, a lens through which I read the book. When we think about Christianity we must consider the many, many unrepresented voices. They are as much a part of the story as Augustine, Luther, Calvin, Wesley, etc. And it's often the silent majority that represents how Christianity actually functions in the world.
Read my full review here: Book Review: Diana Butler Bass, "A People's History of Christianity"