What can I say about one of my favorite Christian philosophers, other than that he not only preached dandling; he lived it. Dietrich Bonhoeffer's theology is amazing: in depth, precise, and unapologetic. His praxis (the way he applied his theology, not only to the Christian communities he formed but to all of Christendom) is life changing. His Christian example is awe-inspiring. I can think of no other modern Christian with a testimony and life story as dynamic as his in a place as dynamic as World War II Germany. From theologian to pastor to rebel to martyr, he took the union he sought with Jesus Christ and made its possibility known to those who doubted it could be achieved. Even at his death, he didn't waver in his conviction.
An excellent biography by Eric Metaxas was written about Dietrich Bonhoeffer, which I thoroughly enjoyed reading. The best way to find out about Bonhoeffer, however, other than by reading his biography or looking up his Wikipedia page, is to read his prolific work. I recently finished Life Together, a book he wrote explaining the communities he set up as a founder of the resistance church in Germany. It speaks volumes to Christian communities everywhere and lays out what is absolutely essential in the lives of believers as they spend them together. He's the author of other books I've read and highly recommend: The Cost of Discipleship and Ethics. No other 20th century writer has challenged me more, pushing me to greater devotion to Christ, not only in dandling, but in pouring out His love to those around me.