Best Software Utilities (Non-IT) List

Here's a list of my favourite, eternally useful list of extremely useful Software Utilities / Tools.

It will be a Forever Updated post, with new additions regularly for Windows - obviously with a slight preference to Java + Open-source versions if competing apps are similar.
For Best Developer Utilities, see this earlier post, Must have tools for the Smart Java Professional.

If an app replaces an existing one, or if there are close seconds, the losing app will move to the Best Software Utilities (non-IT) Honour List.

Find out whats eating your Hard Disk space
WinDirStat: Gives a very unique visual categorization of which files and folders contain what. OpenSource, Windows
FolderSize: A quick way to analyse your usage but without advanced features. Freeware, Windows
JDiskReport: A Java-based disk analyser. Freeware, Java

Recover Lost Files
NTFS Undelete: Free software ported from the open-source Unix version of ntfs undelete utility. EXCELLENT! OpenSource, Windows

Watch any video format without installing codecs
VLC media player: Free all-in-one media player that plays every video format out there without additional codecs OpenSource, Windows