If you have heard seminary students who have never actually read Augustine but who have heard their professors who have never actually read Augustine outline his works/beliefs, then you might be skeptical of the man. He did indeed have some ideas that might seem foreign to contemporary protestantism; he included the apocrypha, he had some strange views on sex and singleness, etc. But if you read through Confessions yourself you will discover two things: he was extremely brilliant and he really loved Jesus and the Scriptures. There is a category of authors in my mind who know the Truth about life, who really know Jesus, and this knowledge compels their writing. Augustine knew the Truth. Sure, there were weird quirks here and there with the concrete details of his theology, but I think if you read him yourself you will discover it is quite easy to forgive him for these. And in fact, maybe some of what we in our modern age view to be "quirky" is actually just wisdom.
The City of God is a really meaningful read. I have always wondered what God's commentary on post-Scripture historical events such as the fall of Rome or the history of the translation of the English Bible or the Reformation, the Renaissance, the formation of the church of England, the Revolutionary war, etc., - I have always wondered what God would say if he were to comment on these events as he did the exodus or the exile. Augustine in no way intends to speak the words of God like Isaiah or Jeremiah, but he does apply wisdom and some seriously robust intelligence to help people understand God's sovereign dealings with humanity and his faithfulness to the kingdom.
I also read On Christian Teaching. I decided to read this last minute because I was also reading Sailhamer's Meaning of the Pentateuch, in which he refers to Augustine's relationship between words (verba) and things (res). Sailhamer argues that modern evangelicals have adopted Augustine's view, namely, seeing the significance of the Word of God in the "things" which the words (signs) point to rather than in the words themselves (as the reformation emphasized). Augustine's teaching led the church to give itself the authority to determine what things meant as they were understood in the mind of God (mens dei), rather than finding the meaning in the words of Scripture itself. Sailhamer likewise argues that evangelicals have simply replaced the authority of the church for the authority of extra-biblical history and archeology. Sailhamer calls for a renewed emphasis on the words themselves, and to look to the discipline of philology to understand their meaning rather than history and archeology.
I am still sorting out this discussion in my mind. There was so much in On Christian Teaching that I really enjoyed. He writes about the importance of Godliness and love in understanding Scripture, and the sheer pleasure of enjoying the literature and beauty of Scripture which can often be neglected by those who draw it out into pragmatic systems. God has given difficult passages of Scripture for the Christian's joy in wrestling with his Word.
So much to discuss with Augustine: body/soul, spiritual death/life vs. physical death/life, freedom of the will, Trinity (I was excited to find he views the Trinity the same as Jonathan Edwards...), memory, time, etc. I will definitely return to him one day.