RidNacs is a free and very fast disk space usage analyzer for Windows. Developed by SplashSoft.de (Stephan Plath)
License: Free
SpaceSniffer provides a visually appealing way to analyze disk usage with a focus on user experience, while RidNacs offers more advanced features like real-time monitoring and disk cleanup suggestions. SpaceSniffer is ideal for users who prefer a straightforward visual tool, whereas RidNacs is better suited for those needing comprehensive analysis and maintenance tools.