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. You can see my annotated Amazon Listmania! list of Psalms commentaries if you want a quick overview of what I think are the most important commentaries before looking more deeply at this more detailed review.
Gerald Wilson's NIVAC on Psalms 1-72 is my favorite of all the Psalms commentaries. It's technically a popular-level commentary, but it's a good deal more in-depth than most NIVAC volumes in the area of Original Meaning, and it's even got a fairly significant introduction, something very uncommon for this series. As with most of them it's very good in its Bridging Contexts and Contemporary Application sections. The main point is to move from the original setting to contemporary application through deriving the general principles behind what the text says in its original setting. Unfortunately, the commentary is incomplete. It really is the first place I look for anything on the first 72 psalms. This one seems to be especially good with theology, and it's got a much greater degree of exegetical detail than some other popular-audience commentaries. [Update: Wilson has died. I'm guessing that this volume will be reassigned (or perhaps completed by someone else as a co-author if Wilson has made enough progress for the publisher to want to use his work).]
The WBC on Psalms is in three volumes. Volume 1 on Psalms 1-50 is by Peter Craigie. It's recently been updated by Marvin Tate, who did the second volume on 51-100, but you can still get the original by Craigie. I haven't looked at the updated version yet, but I imagine it strengthened the weaknesses in Craigie's volume in ways that the series' later volumes tended to improve upon. Volume 3 on 101-150 by Leslie Allen is now in its second edition, with exactly the sort of improvements that I'm expecting Tate did for Craigie. These three commentaries as a set form my favorite detailed treatment of the Psalms. There's some variation among the contributors. Craigie tends to be more theological than the others and is my favorite of the three. He is also strong on comparative linguistics, especially Ugaritic, and practices a moderate form criticism. Tate offers the most detail and is the heftiest of the three volumes (even after the other two have been revised), but he's less theological. Allen is somewhere in between. None of them draw enough connections with the New Testament for my preferences. Craigie's work is also the most dated, though the update by Tate should remedy that. With that update and the revision to Allen, those two volumes are very recent in their current form, and Tate is only 15 years old. All three start with a strong text-critical section and conclude with a summary of the basic meaning, with detailed commentary on each verse in between. There's some contemporary significance in the last section. The original versions of volumes 1 and 3 had much less of that, but the revised versions have a lot more than the originals did. One distracting feature of some Psalms commentaries is over-speculation about which ritual settings each psalm might have originated in, and these volumes focus more on what scholars can say with some confidence.
This is just about the most recent, complete, in-depth commentary on this book. The longest book in the Bible doesn't draw many full-length commentaries very often. There's only one complete academic commentary on Psalms that I know of that's more recent (Terrien), and that's nowhere near as detailed in terms of actual commentary. All three authors stand within the evangelical tradition, somewhat broadly construed. All three of them take views that I'm not willing to endorse in terms of historicity (though I'm not sure I'd deny most of those statements either), but they're all more conservative than you'll find in any other recent academic commentary on the Psalms. Allen is probably the least conservative of the bunch. But this is as conservative as you'll get for now at this level of detail. The forthcoming NICOT by Rolf Jacobsen, Nancy deClaisse-Walford, and Beth LaNeel Tanner might remedy that, but I know very little about the theological perspectives of any of those authors.