This is part of a larger project reviewing commentaries on each book of the Bible. Follow the links from that post for more information on the series, including explanations of what I mean by some of the terms and abbreviations in this post. This is not an exhaustive list, just the commentaries that I think are most worth paying attention to.
My first choice, hands down, is Darrell Bock's BECNT (1994, 1996). It's fairly comprehensive, well-reasoned, easy to read, aware of all the scholarship, and generally conservative. He handles theology more fully than most detailed commentaries (e.g. Marshall, Fitzmyer, Nolland below) and spends a little time on what Luke would have wanted us to take away from the text, which you won't get in very many academic commentaries. This commentary is strong on the flow of argument, taking larger blocks of text to comment on and explicitly thinking in terms of the larger flow at various points, although this usually stops short of what many think of as literary analysis (on which several commentaries below are very strong, sometimes at the expense of everything Bock does well). He does interact a little with Robert Tannehill's work in that area in volume 2, but it's still not a lot. Bock has also written the Acts commentary in this series, but his work on Luke is much more detailed, filling up two volumes, both bigger than the Acts volume. Bock is well-known for his work countering the claims of radicals and skeptics who write about the life of Jesus with the kind of scholarship liked by the History Channel. He's also been very influential in developing and defending progressive dispensationalism, a view that I think is still a little too far in the direction of dispensationalism but is really a different animal and is much more defensible than traditional dispensationalism. I place him solidly in the conservative evangelical camp, and he's taken some criticism for this in reviews, mainly from people who assume historicity and theological agendas are incompatible, something Bock spends a great deal of time arguing against. His scholarship is top-notch. If he's weak anywhere, it's in favoring commentaries over journal articles. Bock has also written the IVPNTC and NIVAC volumes on Luke, but I don't think there's any need to look at the shorter two if you have the BECNT, which you should.
I. Howard Marshall's NIGTC (1978) was, I believe, the first volume of its series. Some of the later authors in the series learned how to use the format a little better to make for somewhat readable works. Marshall's commentary is very dense and technical, and it's not easy to read, especially if your Greek isn't at a relatively high level. Nevertheless, it's one of the best places to go for information (through the work done before it was completed, anyway). Much of the commentary is devoted to matters of Greek lexicography and syntax, and he spends a bit of time on synoptic issues, often with the goal of discerning Luke's theology from what he chooses to use and not to use from Mark and Q. He is strong on Jewish and Septuagintal background. Marshall is recognized by scholars of all stripes as a careful and well-reasoned scholar whose work on the gospels in general has long been known to be among the best. His 1971 work Luke: Historian and Theologian was an outstanding introduction to this book, arguing that Luke's driving theme is salvation through Jesus and that those who point to theological agendas to undermine historicity have engaged in fallacious reasoning. His theological commitments place him in what I would call the moderate camp of evangelicals (which is relatively conservative for Britain but less so for the U.S.). He is also known for defending one of the more radical versions of Arminianism (whereby no one's salvation is secure at any point before death). There may well be more detail in this volume than in Bock's two, but it's harder to parse through it all, and it's not remotely as up-to-date.
Francois Bovon has written a lengthy commentary on Luke, published in French and German, but only the first volume has to date been published in English by the Hermeneia series (2002 but originally 1989). They are planning to translate the whole thing. The first volume covers through 9:50. This commentary is very extensive and easier to read than Marshall, but it still is addressed primarily to scholars. He spends a lot of time on structure, offers lengthy comparisons with Matthew and Mark, and does treat theology and contemporary application in brief. Bovon very clearly writes from a perspective of a believing Christian, which is unusual for this series, but it is still fairly critical in some ways for the work of a believer. The history of interpretation is more important in this commentary than in most. I haven't looked at this much myself, but I expect it's more critical in his conclusions than the above authors. Even so, as conservative a scholar as Don Carson considers his work to be as good on the technical issues as anything else among recent commentaries but much better in terms of theology. Many will question Bovon's view that Luke stems from a third-generation Pauline school and his claim that Luke's gospel was designed to be politically safe in the Roman empire. One reviewer criticized Bovon for being too willing to act as if there is only one purpose for any given narrative, and the same reviewer also thought he was more focused on the trees at the expense of the forest, particularly when it comes to thinking about how each pericope relates to the whole.
Joseph Fitzmyer's AYB (1981, 1985) is a real work of scholarship by one of the most respected contributors to this highly-respected series. He is usually pretty distant from the text's claims in terms of historicity, and there's a lot of redaction criticism here, which I think can sometimes be distracting (and overly speculative), but he's strong on linguistic matters and does reflect on theology, especially in the introduction. He has an amazing command on the Semitic literature through the first century and thus does a very good job with the Semitic background of the book. He spends more time than some on the overall structure and flow of the book. He posits a late date but does think the book was written by Paul's companion Luke. Marshall at one point referred to Fitzmyer's commentary as the best on Luke. Fitzmyer later wrote the commentaries on Acts and Philemon in the same series, and his I Corinthians is due out soon.
John Nolland's WBC (1990, 1993, 1993) is yet another very detailed work, taking up three volumes. I find the format of this series to be extremely annoying, and it really detracts from either reading straight through or trying to find what the author has to say on any given verse. There's no question of Nolland's research into the scholarly issues, however, and it may well be that if you can navigate the awful format you'll find more here than anywhere else in terms of finding a guide to the scholarship on the book. Carson complains that Nolland is so good at presenting the conclusions of various authors that you get no sense of which arguments he thinks are good. But you'll certainly get a feel for what views are out there with Nolland's commentary. I think it's probably most accurate to describe Nolland as a moderately-critical evangelical. This commentary spends a lot of time on redaction criticism. There's so much detail on the state of scholarship and so comparatively little simply looking at the text that I think it would be hard for the average preacher or Bible study leader to get a lot out of it without spending an inordinate amount of time.
Joel Green's NICNT (1997) seems to be a love-it-or-hate-it book. Some reviewers even hesitate to call it a commentary. His specialty is on discourse and narrative analysis, and he brings in sociological background when he finds it important to do so. I've seen him complain in reviews of other commentaries that they ignore the social context that he spends so much time on, but he ignores a different kind of social context, which is the community of Jesus traditions forming at the time, including the other gospels. He hardly ever deals with issues involving the other gospels or the historicity of anything this gospel reports. He also doesn't really work through the text in order in a typical way for a commentary. He simply discusses the literary nature of this gospel. In general, I prefer a more balanced approach, but someone who wants a supplement that looks at the gospel from this sort of perspective may appreciate Green's work. Green contrasts with Nolland in not discussing other scholars directly
much at all but simply focusing on his own reasoning for his own view. In perspective, Green is probably toward the leftward end of NICNT contributors. He was one of three mainline Protestant authors of a fairly well-received introduction to the New Testament, many of whose positions seem to me to be more critical than the evidence warrants (and notably lacking in conservative evangelical citations for some of its sections, but I don't know if it was Green who was responsible for that; it could have been one or both of the other authors). Green is also editor of the IVP Dictionary of Jesus and the Gospels, which is an excellent resource, and (I believe) the first of what has become an outstanding series of dictionaries on the different parts of the Bible. He's also the author of I Peter for the Two Horizons commentary series.
Luke Timothy Johnson's Sacra Pagina (1992) is also stronger on literary discussion than other matters, and his attention to the overall work treats Luke-Acts as the work. Probably his most striking contribution is in connecting passages in Luke in the overall context of Luke-Acts. This is a Roman Catholic series, but Johnson isn't a typical Catholic (for example, his James commentary defends James and Paul's consistency in almost Protestant terms, and his views on gender don't fit well with Catholic practice). Johnson has also written the volume on Acts in this series and the AYB commentaries on I and II Timothy and James. He's done a lot of good work responding to the Jesus Seminar, although I was disappointed to find out that his excellent book on that topic ends badly when he simply stops defending the Bible's historicity at the point of the resurrection, the most important historical event for Christian faith. This commentary hardly deals with historicity issues at all, though. Johnson tends to compare Luke with Greco-Roman literature and rhetoric.
In some ways, I think Robert Stein's NAC (1992) may currently be the best mid-level commentary on this book, although it doesn't actually have very much competition. Most of the above are pretty thick commentaries, several of them multi-volume, and there isn't a lot in between them and the lighter, more popular-level works. Stein's is much more manageable for someone who doesn't want to review lots of scholarship but just wants some reasoned arguments among a more limited set of possibilities, but it is very strong on exegesis and one of the most detailed commentaries in the NT part of the NAC. One unusual thing about Stein's commentary is that it spends a lot more time than I would expect in a mid-level work on synoptic issues. I wouldn't expect those issues to be as central for the expected audience of this series, but this isn't by any means the kind of in-depth redaction criticism that you'll find in Fitzmyer or Nolland. It's more of a summary of the conclusions of what his own scholarly study of redactional issues means for Luke's theology and emphases. He doesn't even call it redaction. It's "composition criticism".
Walter Liefeld's EBC has been revised by David Pao (2007). I haven't seen this, but Liefeld's commentary was one of the better light commentaries on this book, and I've heard nothing but good things about Pao from his students at Trinity Evangelical Divinity School. Liefeld's commentary was originally bound with Matthew and Luke in the old EBC series, but the revised version puts it with John and Acts. At this point I think this should be the leading lighter commentary on this book.
One very important short commentary is Leon Morris' TNTC (rev.1988). It really is brief, but Morris often has a lot of good stuff to say. I find it doesn't answer a lot of the questions I ask, and it doesn't give much argument when it does, certainly not to the point of comparing lots of other views. But it's pretty good as a quick, general guide to the basic meaning of the text with scholarly understanding behind his comments even if his reasoning isn't always on the surface.
Craig Evans has also done a popular commentary in the NIBC (1995). It's especially good in Old Testament and intertestamental background. Evans has done the much more detailed WBC on the second half of Mark and is working on the first half. He's one of those evangelicals whose work is fully appreciated even by most critical scholars but may be seen as sometimes a little too critical by some of more conservative evangelicals. It's worth being aware that this is Craig A. Evans, not C.F. Evans, who has written on Luke from a much more critical point of view.
Besides Bovon's remaining volumes, several detailed exegetical works are in the works. David Garland is doing Luke for the new Zondervan Exegetical Commentary series. That will be excellent by an conservative evangelical who already has published on Matthew and Mark (not to mention I Corinthians and Philippians).
Richard Bauckham's ICC will become the new standard. Bauckham is one of the most interesting, innovative, and careful scholars in biblical studies today. I consider him a moderate evangelical. His recent book on eyewitnesses and the gospels is absolutely excellent and is making considerable waves in scholarly circles. His commentary on II Peter and Jude is still the standard work on those books 20 years later, and I expect his ICC on Luke to last even longer than that. He's also contracted to do John for NIGTC. Since those are both major projects that might take decades each, I do hope he can manage to get them both done.
John T. Carroll is doing the NTL. I believe this will be Carroll's first commentary, but he's published a lot on Jesus and the gospels. He teaches at Union Theological Seminary, an institution with a history of good scholars among the mainline Protestant denominations. This series is more readable than most academic commentaries, but it's not designed for a popular audience, despite at times pretending to be.
At the intermediate level, I expect Peter Head's PNTC to take over as the best intermediate commentary on this gospel. Head is very well-known in textual criticism circles. He's also been the head of Tyndale House for quite a while (although I believe he's now stepped down).
Loveday Alexander will be doing the BNTC. This is an intermediate-level series. I believe she also has not published any commentaries before, but she has written a lot on Luke and Acts. She holds an Oxford professorship and focuses much of her research on the Greco-Roman background to the New Testament.
Amy-Jill Levine and Ben Witherington III will be doing the NCBC. Levine is Jewish and tends to be on the more critical end, especially offering feminist analyses, but I find her to be more open to conservative views on other matters than many non-Christian scholars are. (For example, she's attacked the double-standard against Jews who become Christians remaining Jews while Jews who become atheists can happily remain Jewish. She insists that the New Testament isn't as far from Judaism as most Jews assume.) Witherington is a moderately conservative evangelical Christian. Witherington is strong on social background and rhetorical structure, and he likes to defend the historicity of the gospels against Jesus seminar types. His Acts commentary is outstanding. Scholars regularly complain of too many typos, incorrect references, and other minor errors in his commentaries, but perhaps having another hand involved would help with some of that. I have a hard time imagining what these two together will be like, though.
There's a fuller list of forthcoming commentaries under Luke here.