"What is the book that changed your life? (not novels or religious texts)"
I think it's a wonderful way to connect in a less superficial way and learn a little more about each other. It's also a wonderful way to discover new books worth reading.
This is one of them (the full list is here):
When stakes are high, opinions vary, and emotions run strong, you have three choices: Avoid a crucial conversation and suffer the consequences; handle the conversation badly and suffer the consequences; or read Crucial Conversations and discover how to communicate best when it matters most. Crucial Conversations gives you the tools you need to step up to life's most difficult and important conversations, say what's on your mind, and achieve the positive resolutions you want. You'll learn how to:
Prepare for high-impact situations with a six-minute mastery technique
Make it safe to talk about almost anything
Be persuasive, not abrasive
Keep listening when others blow up or clam up
Turn crucial conversations into the action and results you want
Whether they take place at work or at home, with your neighbors or your spouse, crucial conversations can have a profound impact on your career, your happiness, and your future. With the skills you learn in this book, you'll never have to worry about the outcome of a crucial conversation again.