crossdirstat VS Folder size (by RoteBetaSoftware)

TreeSize - TreeSize tells you where precious disk space has gone to.

TreeSize Professional - TreeSize Professional is a robust Graphical Manager developed by JAM Software to help you perform different operations on your storage systems like analyzing the data, organizing and freeing up the storage system effectively, and viewing the usage.

Baobab - Distributor of workload automation, financial statement reporting, data access, IT Asset Management and Service Desk software solutions.

Folder Size Catalog - Folder Size Catalog is a handy solution that offers a detailed view of your folders sizes to enable you to find the disk space distribution with great ease.

SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.

DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.