Unless you have extensively read the Fathers of the East, especially the Three Holy Hierarchs (John Chrysostom, Basil, and Gregory the Theologian), I would not be so quick to exhalt Augustine over any of them. Believe it or not many of the Eastern Fathers had every bit as much influence over Roman thought as did Augustine. In fact, if I remember correctly Aquinas quotes St. John of Damascus at least as much, if not more, than Augustine in the Summa.
Please remember also that while Augustine does carry a great deal of weight in Western Latin/Roman Catholic thought, he carries nearly no weight in Eastern Byzantine Catholic thought. So when you say “he contributed more to Catholic thinking” your statement is actually inaccurate. It would be better to say “he contributed more to Roman/Latin thinking”.
Finally, there are other minds in the West equally as brilliant, albeit not as influential. You’ve already mention Aquinas, which is a good start. An equally brilliant theologian and doctor of the Church that most people overlook, however, is St. Bonaventure; who’s works have a more “mystical” leaning than do the works of Aquinas, but they are every bit as intellectual. Also one must not overlook St. John of the Cross. Although his works aren’t “intellectual” but rather “mystical”, nevertheless he was one of the more brilliant minds of his time, he just chose to cast off the intellectual field because he believed it was insufficient to express the truth of God, a truth which can only be understood through experience (a very Byzantine notion). There are also many modern theologians who are having as much impact on the Roman Church today as Augustine; e.g. Ratzinger/Pope Benedict, Hans Urs von Balthasar, Henri de Lubac, Jean Danielou, Pope John Paul II, etc. By exhalting one theologian over others, no matter how ancient that theologian is, we run the risk of ignoring the great contribution of other theologians, and developing an overly one-sided theological expression.