Eat That Frog! (Brian Tracy)- Lots of useful productivity tips. Motivating and practical.
Bleachers (John Grisham) - I learned a lot about the culture behind American Football and school/college sports.
The Wide Lens (Ron Adner) - I learned a systematic approach towards evaluating ideas and the environment around them so that I could determine what needs to change (outside of my innovations) that must be encouraged for my ideas to succeed.
The Martian (Andy Weir) - I got a "feel" for living on Mars being a reality potentially sooner than I appreciated.
Brownlow North (K Moody Stuart) - A book about a Scottish Evangelist. It was superb to see where he started from in his preaching, how he differed from everyone else, and how that was probably the key to his startling effectiveness.
Songs of the Spirit: The Place of Psalms in the Worship of God (Ed: Kenneth Stewart) - I learned an appreciation for the book of Psalms, though written long before it, it is clearly (by how it's written, what it discusses in the past tense, and what's only understood now) FOR the New Testament church.
In my Father's House (Corrie ten Boom) - a beautiful insight into what a Christian household can look like.