Qt-based directory statistics
Sadeaner is a good tool for cleaning up the PC
A disk usage statistics viewer and cleanup tool for Windows
Graphically shows disk usage for Macs
Visualize files on disk with file size
Ncdu is a disk usage analyzer with an ncurses interface
A modern graphical SSH client
Examine your file collection: what's backed up; disk usage.
Free up valuable disk space
An application that controls disk drive space