I'm a new member; you can read my introduction in the appropriate thread. As a specialist in biblical studies, we rely on scholarly commentaries to provide insight into the social location and context of documents (we rely on them for other things too, but for right now I'm concerned chiefly with commentaries like Hermeniea and the New International Greek Testament Commentary). Another new series I really like is Baylor's "Handbook on the Greek Text" volumes. Rather than being a commentary proper, they are an analysis of the book's Greek, construction by construction. This is helpful because it provides a kind of lexical overview that would normally be a long time in coming; for example, the first note in the volume on the Acts of the Apostles notes that the author usually uses "men" without "de," something it would take a reader a lot of reading in the book to figure out, if they ever read the whole book in Greek (often translation only deals with a few chapters here and there, as most of you know).
All that is to say, are there any commentaries like this for major Greek works outside the Christian canon? Do commentaries exist that treat the Greek text in great detail rather than simply being a history book about, say, Plutarch or Aristotle? I know that commentaries exist for major Greek texts, although not in the volume that exist for the Bible. What are some of the best commentaries that you know of or have worked with? What do you like about them?