I use Windows. Not a complete list of course and in no particular order, but some of the programs I use are:
Roboform (password manager)
http://www.roboform.com
EditPad Lite (text editor)
http://www.editpadpro.com/editpadlite.html
Fences (desktop organization)
http://www.stardock.com/products/fences/
ObjectDock (desktop organization)
http://www.stardock.com/products/objectdock/
Update Notifier (update utility)
http://cleansofts.org/view/update-notifier.html
The Bat! (email)
http://ritlabs.com/en/products/thebat/
Axcrypt (encryption)
http://www.axantum.com/axCrypt/
KeePass Password Safe (password manager)
http://keepass.info/
VLC (media player)
http://www.videolan.org/vlc/
USB Safely Remove (usb device manager)
http://safelyremove.com/
PDF-XChange (pdf viewer)
http://www.docu-track.com/home/prod_...s/pdfx_viewer/
WhoCrashed (crash dump analyzer)
http://www.resplendence.com/whocrashed
Unlocker (unlocking utility)
http://ccollomb.free.fr/unlocker/
PowerArchiver (archiving utility)
http://www.powerarchiver.com/
GoodSync (synchronize)
http://www.goodsync.com/
BounceBack Essential (backup/pc recovery)
http://www.cmsproducts.com/products/...essential.html
Active Hard Disk Monitor (disk utility)
http://www.disk-monitor.com/
SpeedFan (hardware monitor)
http://www.almico.com/speedfan.php
IMatch (digital image management)
http://www.photools.com/
Mozilla Sunbird (calendar)
http://www.mozilla.org/projects/calendar/sunbird/
Irfanview (image viewer)
http://www.irfanview.com/
FastStone Capture (screen capture utlity)
http://www.faststone.org/
ConceptDraw (diagramming software tool)
http://www.conceptdraw.com/en/products/cd5/main.php
Recuva (file recovery)
http://www.piriform.com/recuva
I am
NOT an affiliate,
NOR am I associated with any of the above companies.