Commentaries are an interesting blessing. Most of us have access to various commentaries, both in print, perhaps in software form and online. For some they can be a crutch that bears all the weight of their study – they simply look up what their favorite expert says about a passage and preach that (sometimes with all the grace of a person walking with one crutch and no legs!) For others commentaries provide conversation partners – the opportunity to interact with an expert or two regarding their take on a passage. For some commentaries can be both conversation partner and source of frustration.
Why frustration? Well, often the commentaries we look in are too atomistic in their approach to the text. They move from one word or phrase to the next with relatively little comment on the flow of the text, the flow of thought, the implications of the broader context. Some commentaries become a source of word study information and grammatical analysis, but fall short of the discourse level awareness that we need in order to more fully understand and preach a passage.
So I am wondering . . . have you used a commentary recently that proved really helpful in your sermon preparation? Not just in terms of the details, but also in terms of the flow of thought? It could be a technical commentary from the NIGTC or WBC series, or a literary-driven work like Fokkelman’s voluminous work on Samuel, or it could be a “paperback” like Donald English’s little work on Mark for the BST series. Sometimes the paperbacks are more aware of flow of thought than the heavyweight commentary siblings on the shelf. Anyway, we’d all be interested to read any recommendations for helpful commentaries – helpful conversation partners in the often lonely work of sermon preparation.
Biblical Preaching 
No specific commentaries come to mind as far as keeping the ‘big picture’ and ‘flow’ in mind. But I have found it very beneficial to refer to Bible Dictionary articles on a particular book.
As I am preaching through Matthew right now, the Tyndale Bible Dictionary article on the book of Matthew has been very helpful to me in keeping the major flow of the book in perspective. I then consult the commentaries for the details.
I have found that the dictionaries basically make an “expert” on a particular book boil it down to a very terse overview, thus forcing them to stick to the big picture and skip the details (“Give us a commentary outline on the book of Matthew in 1,000 words or less”). What you end up with is the ‘cream’ of their expertise on a particular book. Of course, your mileage varies depending upon the dictionary consulted and the author of the particular article.
I really like the Zondervan Life Application Commentaries. They provide several different views of the text. They look at it exegetically, in its historical-grammatical context but then they look at its application. They do not intermingle this together however, they have a few sections for each passage. I like their approach, check it out. It does take a lot of time to read all the stuff for each passage though.
I’m currently preaching through the Gospel of John and regularly seek insight from MacArthur, Kostenberger (BECNT), Carson (PNTC), and Morris (NICNT). However, my favorite John commentary is one of the shortest. Merrill Tenney’s John: The Gospel of Belief is both concise and insightful. I highly recommend it even if you already own Tenney’s commentary on John in Expositor’s Bible Commentary.
In preaching through John I found Press Study Commentary by Gordon Keddie very insightful. Generally I find Christian Focus commentaries helpful. And any commentary by Phil Ryken or Richard Phillips (especially on Hebrews) is an excellent choice!