2008 is now here, and maybe its a good idea to share what you use on a regular basis (with release number if possible). There's a lot of good stuff out there for Windows that probably quite a few know little about or haven't tried.
Web browser: Opera 9.25 (default), Mozilla Firefox Portable 2.0.11, Opera USB 9.23
Documents/presentations: Microsoft Office 2003, OpenOffice Portable (if the MS programs can't open a file)
Anti-Virus: Kaspersky Labs 7.0
Anti-Spyware/Malware: Kaspersky Labs 7.0, SpyBot Search and Destroy, a-squared (free version)
Audio Player: foobar2000 0.9.5
Video/DVD Player: The KMPlayer 2.3
IM: Pidgin 2.3.1 (handles all IM protocols, AIM, MSN, Yahoo, Jabber, etc.)
Image Editing: Microsoft Digital Image Pro 9.0
Video Editing: Windows Movie Maker
Audio Editing: Audacity
Audio Compression: FLAC 1.2.1 (lossless), LAME mp3 3.98 (lossy)
Video Compression: XViD/DiVX (avi), Windows Media Video 9.0 Professional