Chip Ingram's book on a Christian's spiritual battle between Satan and his evil forces is a balanced take between the extremism of seeing a demon under every rock or ruling out the existence of demons altogether. This book is broken down into 4 sections, with each section receiving an executive summary of the main ideas with all the pertinent Bible verses at the beginning. This makes the book an incredible resource on the topic of spiritual warfare. Much of the book focuses on Ephesians 6 and the armor of God, with each piece of armor receiving it's own chapter. I was pleasantly surprised at the depth each chapter uncovered on how these pieces of armor would have been understood by 1st century Christians given the Roman soldiers use of such armor. It truly brought this passage to life for me.
While I haven't read tons of books on this topics, among those I have read, I would recommend this book as the most balanced and scripturally grounded.
You can check out more details on the book at Amazon.com.