Web browser
Firefox
Google Chrome
 
Anti-Spyware
Ad-Aware
Spybot Search & Destroy
Spyware Blaster
MS Security Essentials
 
Antivirus
Avast Free Antivrus
AVG Antivirus Free
MS Security Essentials
 
Tweak/Cleanup
CCleaner
Defraggler
Recuva
Glary Utilities
FCleaner and RAMRush

Utilities
Unlocker
Universal Extractor
 
FTP
Filezilla
 
PDF
PDF-XChange
 
Burning/Ripping
Imgburn
 
Media Players/Editors
VLC Media Player
Audacity Audio Editor