Derek Kidner does an excellent job in this commentary on the book of Psalms (divided into two books, Ps. 1-72 and Ps 73-150). As I'm finding with most of these commentaries, the introduction is priceless and in a lot of ways more helpful than the commentary itself because in it, Mr. Kidner draws the big picture of the psalms, who wrote it, the structure of poetry, the theology contained within it, etc.
As with his other commentaries, Mr. Kidner covers the material well, but is blessedly short in his comments.