I found Imam Ghazali's Mishkat Al-Anwar an awesome book. Many parts of the book amazed me and left me in awe of the author. A truly mind expanding experience.
Imam Ghazali takes the Light Verse from Surah Nur of the Quran and writes a book on it:
"Allah is the Light of the heavens and the earth. The Parable of His Light is as if there were a Niche and within it a Lamp: the Lamp enclosed in Glass: the glass as it were a brilliant star: Lit from a blessed Tree, an Olive, neither of the east nor of the west, whose oil is well-nigh luminous, though fire scarce touched it: Light upon Light!" - Quran 24:35
He first explains what the verse means, and explains man's relation to his creator. Then before he finishes the book, he delves into the inner machinations of the cosmos and how it all services Allah.
This book will blow your socks off. But be warned, this is a philosophical book, that reaches some very deep levels. Anybody ready for deep philosophy and willing to examine man's relation to God, will find this book very illuminating.
Lastly, I believe that the translator/commentator tried to write a useful commentary, but he came at the whole book/concept from a non-Muslim viewpoint. The viewpoint is alien to the Muslim mindset, and could be considered unIslamic.
Some people might find the commentary useful, I found it unuseful.
There is a more expensive version with better type-print etc by David Buchman (Translator).