Here are a few brief thoughts on Psalms commentaries based on my study this summer:
1. Nothing comes even close to Spurgeon's Treasury of David (this is really "must own" stuff).
2. Kindner's 2 Volume Tyndale Commentary is very good (Volume 1 and Volume 2).
3. Wilcock is weak (which is sad to me because I love all the other Bible Speaks Today commentaries that I've worked with).
4. Both Boice and Lawson have good homiletical Psalms commentaries.
5. The Messiah in the Psalms by Belcher is a good read with lots of helpful Christ-focused applications.