Some days ago a stumbled upon this tool: http://www.jam-software.com/treesize/
A free version is available for download, with limited capabilities.
The commercial version adds more powerful reporting features as well as allows connecting and getting information from a network share.
You can perform several type of analysis, and get back an output in different formats (Excel, Csv, Html, etc…)
I strongly encourage you to give it a try.
I’m using it mainly in two different scenarios.
First and foremost, which may seem obvious, when I need to free some disk space (I always run out of disk space…).
Then, and this is happening more and more frequently, as a way to discover permissions and storage usage on shared drives and folders.