The BestCommentaries.com website run by John Dyer offers a valuable resource for the student of Scripture. He manages a comprehensive list of commentaries on the Bible, especially of multi-volume series. Volumes are given tags defining the type such as technical or devotional. Many volumes are rated based on other published listings and by members of the site. Links are provided to sellers of the volumes, both hard copy and software, and now also to Accordance! My only criticism is that with so much data the pages can load rather slowly.
Here are some screenshots to whet your appetite.
This page ranks the major commentary series volume by volume: