Google Pack is a package of free software that Google feels is essential.
Lifehacker.com has also posted their own
Lifehacker Pack. While this isn't a comprehensive list of all my favorite free applications, these are the ones I use on a near-daily basis.
OpenOffice.orgThis one was a total "gimme". I first gave this a try over a year ago I was too lazy to try to find a bootleg copy of Microsoft Office. Now I actually have a legit copy of Microsoft Office installed but I still find myself using OpenOffice.org more. Why is that, you ask? It handles more formats, does a decent job of exporting your documents to PDF, and my "basic" version of Microsoft Office did not include Powerpoint.
Mozilla FirefoxI shouldn't have to explain this one anymore. NEXT!
Avast AntivirusThis antivirus software is very easy to configure, fast and easy automatic updates, and not intrusive. Oh, and licenses are 100% free for home users.
CCleanerSometimes referred to as "Crap Cleaner"-- it does quite a nice job of cleaning up unnecessary files that installers and uninstallers leave behind. It can also go through your registry and remove most invalid entries. After running this for the first time I freed up approximately 400 MB's and reduced my Windows startup time dramatically.
The GimpIt's like Adobe Photoshop, but free and open source. For the casual Photoshopper it has pretty much everything you'll ever need.
TextPadThis is currently my text editor of choice while working in Windows. You can open several large text files in a single window and it will keep on going. Try doing that with Notepad!
TaskSwitchXPAn alt-tab replacement for Windows XP that behaves a lot like Mac OS X's Expose. It only takes up around 600 KB of RAM on my computer. Once you try this there's no going back.
VLCThis media player plays everything that the big guys choke on. It even lets you play DVD movies from outside your region, and helps you get around Macrovision protection so you can output to older TV's.
iTunesThis is the software that finally got me to organize my music collection, and made it very easy to do so. I can no longer imagine organizing music without a quicksearch feature or smartlists.
Google EarthOMG I CAN SEE MY HOUSE!!!!!111eleven
PicasaI often refer to this as the "iTunes of Photos". Currently I am using it to keep track of my collection of wallpapers. I'm sure that if I had a digital camera I'd use it even more.
RainlendarDisplays your calendar and Outlook events on your desktop, while taking fewer resources than Konfabulator would while doing the same thing.
FileZillaFree, open source FTP client that is really easy to use.
Is there anything you feel is missing from this list? Leave a comment!