Go here for Google Book hyperlinks for volumes from the NICOT (New International Commentary on the Old Testament) and NICNT (New International Commentary on the New Testament), and much of the material can be viewed without purchasing books.
This is an excellent resource. Last year I read front to back the hardback NICOT/NICNT commentaries by Peter Craigie (Deuteronomy) and Leon Morris (Gospel of John) and both were excellent. I recently picked up the hardback commentary on Acts by F. F. Bruce, and I look forward to reading it, but I won’t start until I finish Tim Grass’ recent biography of F. F. Bruce (started reading that biography this week).