I think the concept of systematic theology and biblical theology is deceptive. I have studied both and I think I can strip away the confusion by providing a non academic answer that sort of throws the curtain in front of the wizard of Ozz to one side.
Let me explain and hopefully this makes sense as I am going out on a branch a bit here with potential negative feedback.
Organizing the understanding that one has when reading the Bible has been termed by somebody as systematic theology. It means nothing. Yes possibly under Newtonian physics where the universe was considered like a clock, some theologians became overly dogmatic. Yes, yes, so what. Yes, after Einstein and theories of relativity we prefer more organic models of thought and we are post-modern and all that, but who really cares. Newton still dominates most of physics anyway.
The truth is, an understanding is by nature somewhat systematic, in that it organizes what would otherwise appear as just random things, tries to make sense of it, daws conclusions and then tries to fit new things into the 'understanding' as it progresses. When something new (new Bibles verse for example) does not fit (into our theology) then we try to revise our understanding until it does. Eventually we developed a system of beliefs like 'Calvinism' or Arminianism and people call it a systematic theology.
To answer the question then. The greats are whoever you consider as having a great understanding. The other side of this coin is not Biblical Theology. There is no other side of the coin. Biblical Theology is more like a preferred organic technique of adhering to a natural progression of scripture and avoiding the dogmatic assertions that would otherwise too quickly digest scripture into ones own belief system. We as 'organic thinkers' tend to prefer to leave things as they are and not always have a direct link into a system. In the end however, there is nothing in this method that was not already performed by some systematic theologians. Biblical Theology is therefore nothing but a word in some ways. A word created by people who prefer to explain things in a different way and eventually use it to create their own systematic theology.
I have explained the basic core subtle difference between the old systematic thinkers and the systematic thinking of Biblical Theology here. I consider this subtle difference sinister as Biblical Theology in its quest for the 'unfolding flower' does not like the sudden violence on the cross in how it radically changed the covenant. When I studied Biblical Theology through one of the colleges who have popularized it into today's world, I found that it tried to synthesize the covenant of the Old Testament to the New as though there really was no difference at all. All in the name of a slow progression. Ironically I think this makes Biblical theology is not biblical on this most important point.
When we consider our theology to be simply our understanding there is only Systematic Theology and if the term Biblical Theology had never been created it would not have a significant impact on what understanding we have. The emphasis in Biblical Theology that is good and always was understood by the better systematic theologians, is that the scripture is not like a manicured garden, with every leaf in its place. It is not Calvinism per se. The scripture is more like nature with a big rock here, where it should not be, and something else there for some strange reason. Yet the whole of it is much more amazing and beautiful that way. Ironically the person who said this was Charles Hodge, the last of the systematic theologians at Princeton before his predecessor started the department of Biblical Theology (as though Hodge's Theology needed improvement! ) In my own view this was the beginning of a theological decline at Princeton. Hodge is an excellent Bible commentator that as far as I know has not had an equal from Princeton since.