Hoyd's Recommendations
All software that I recommend is FREEWARE unless otherwise indicated. These are all the files that I install immediately following a format since I use them the most and they are all must haves.
Anti-virus
AVG Anti-virus - http://free.grisoft.com/freeweb.php/doc/2/
Internet Browsing and Email
Mozilla Firefox Browser - http://www.mozilla.org/products/firefox/
Sage - read RSS and Atom feeds within Firefox
Adblock - block unwanted ads - adblock-hnn.txt
BugMeNot - automatically fill in login forms online with anonymous data from BugMeNot
IEView - launch Internet Explorer to view your current page
Copy Plain Text - copy highlighted selections to the clipboard without the formatting
Web Developer - package of useful web design tools
FoxyTunes - control most media players from the status bar
MouseGestures - use the right button and an action to browse the web
Download Them All - filter links on a page and then download selected files
Nuke Anything - temporarily removes an item from the page
Download Manager Tweak - change appearance/actions of the Download Manager
Mozilla Thunderbird Email Client - http://www.mozilla.org/products/thunderbird/
Spyware/Adware Removal
Ad-Aware - http://www.lavasoftusa.com/support/download/
SpyBot Search & Destroy - http://www.safer-networking.org/index.php?page=download
CD/DVD Archiving
Nero - http://www.nero.com - * not Freeware but is included with many burners
DVD Shrink - http://www.dvdshrink.org
File Sharing
Kazaalite K++ - klitekpp243e.exe
Azureus - http://azureus.sourceforge.net/
Media Players
iTunes - http://www.itunes.com
Matroska Pack (Codecs) - http://packs.matroska.org
Divx and Xvid - http://www.divx.com/divx/download/index.php
Real Alternative - http://www.free-codecs.com/download/Real_Alternative.htm
Media Player Classic - http://sourceforge.net/projects/guliverkli/
Winamp 2.76 Lite - winamp276_lite.exe
Power Toys
Power Toys for Windows XP - PowerToySetup.exe