For more than 20 years I was interested in Orthodoxy. During this time I read many books about Orthodoxy. I also read critiques of Orthodoxy, and I read the Fathers of the church. Like many others, during these two decades I was thinking that one book--or the "right" series of books--would convince me either to accept or reject Orthodoxy.
You see, there is this temptation to believe that one can read his way into (or out of) Orthodoxy. In fact, that temptation persists not just concerning Orthodoxy but concerning most religions, whether they are Christian or non-Christian. The thought is that, when we're searching, we'll stumble along the right book, the right set of words or the right argument that will make everything click. It's not unlike trying to conjure a vision so that you might believe. But vision conjuring is putting God to the test. And reading yourself into Orthodoxy is forcing the Church to be an academic endeavor when, in fact, she is body of Christ animated by the Holy Spirit in the lives of the saints and faithful.
If one pursues the course of reading one's way into the Church, then one may end up very knowledgeable about Orthodox teachings, but not yet understanding the Church or her life; and so not yet Orthodox. It's rather like reading one's way into a family or believing that taking a class in "being a good sister or faithful husband" will actually achieve that end.
Let me suggest, then, that the better way is to understand the purpose of books and teaching as these relate to the Christian faith and life. Books, catechesis and instruction exist not to impart a body of knowledge so that one might become convinced or perusaded about the correctness of a belief. Rather, books, catechesis and instruction are provided to help explain what one has already experienced in the body of Christ. The liturgy is, most chiefly and commonly, this experience of the Church. So books, catechesis and instruction in the faith exist to explain the what, the how and the why of the catholic and godly living that is the liturgy. Or, put more simply, one ought to attend regularly an Orthodox worship service (Byzantine or Western rite) and allow various Orthodox books (like those by the good Bishop) to explain why the Church worships as she does.
So when asked "What one book [or author; or series of books] influenced you to become Orthodox," I increasingly give this answer: "The Liturgy. When I began praying the hours and celebrating Mass without editing the prayers, without trying to 'Lutheranize' them; when I took them at face value and prayed them as they were given, then I began to understand the catholic faith--which, in turn, led me to embrace Orthodoxy as the one true Church."
Incidentally, my decision to pray the Western liturgy without emendation was coupled by my decision to read the Fathers the same way. So when I began to read the Fathers the same way--not forcing them to speak 'Lutheran' but embracing them (foibles and all) in their own context--then I began to see that the inadequacy of the interpretations I had preached, the teachings I had taught, and the phrases I had learned and used. And, at the same time, I began to understand more clearly not only how the Church spoke and what she meant, but even more importantly how the Fathers truly intersected with the liturgy.
Admittedly, this took a while. But not nearly as long as the 20 years of "interest."