Recommended Software
Always read the EULA and Terms of Use before installing any software.
Software marked with a 
is highly recommended.
Audio & Video
Audacity - Audiograbber - Media Player Classic - Miro - QuickTime Alternative - Real Alternative - Songbird - VLC Media Player - Winamp
Backup & Compression
CDBurnerXP - Cobian Backup - WinRAR
Browsers
Firefox - Opera - Google Chrome - Safari
Drivers
ATI Catalyst Drivers - ATI Catalyst Drivers Vista - NVIDIA Forceware - NVIDIA Forceware Vista - .NET Framework Version 3.0 - DirectX - Java Runtime Environment - Logitech SetPoint
Email & IM
Google Talk - Skype - Thunderbird
Imaging
Blender - Dia - Google Earth - The GIMP - Picasa
File Transfer
Network Tools
HoverIP - UltraVNC - Wireshark(Ethereal) - Advanced IP Scanner
Office & PDF
Adobe Reader - Foxit Reader - Sumatra PDF - OpenOffice.org - PDFCreator
Security
AVG Free Edition - Ad-Aware - ClamWin - HiJackThis - Spybot - ZoneAlarm Free - Malwarebytes
System Tools
CCleaner -
Process Explorer -
Speed Fan -
Unlocker -
The PC Decrapifier