Disk Usage Reports - Disk Usage Reports is a web-based way to view disk usage on remote computers or servers, or to...
ncdu - A disk usage analyzer with an ncurses interface, aimed to be run on a remote server where you...
TreeSize - TreeSize tells you where precious disk space has gone to.
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Filelight - Filelight is an application to visualize the disk usage on your computer.
WizTree - WizTree quickly finds the files and folders using the most space on your hard drive. It scans the MFT (Master File Table) instead of crawling the entire disk which makes it very fast.