yeah, I don't do much image editing any more.
I use chatzilla on my laptop

I'd feel naked without winRAR. It's a great zipper/unzipper that integrates really well into your right-click functions and takes a minimum of fuss.

I actually prefer Tugzip

Never heard of that one. I'll give it a try... that reminds me: 7-zip is also pretty popular.

Looks like we'll get enough software that I'll have to sort the index by category :) . TugZIP seems a bit too full-featured for my old WinRAR habits, but it looks very nice as a filemanager. If only it would run applications in their own directory, instead of the desktop.

Scribus
Page layout / desktop publishing.
Synfig
2D animation tool (highly buggy, but rather powerful). Dual/Quad core users may have a few extra issues, so read the readme.
K-Light Mega Codec Pack
Not a program, but a good collection of audio/video codecs. Comes with Media-Player Classic.
FileHippo Update Checker
Scans your PC and lets you know which programs have a new update out.

Blender is a great free 3d modeling program.
wegame is a great video capture client that's also free. I'd prefer it to fraps, if only it had a higher compatibility setting.
Camstudio is a great video capture program as well, works great with dosgames, also captures desktop videos. The only issues I've had with it, is properly detecting my sound card, I have to collect the input on my microphone instead.. but it will record virtually anything you see on your screen.

Ubuntu (IPA: [uːˈbuːntuː] in English,[2] [ùɓúntú] in Zulu) is a computer operating system based on Debian GNU/Linux, a popular Linux distribution. Its name comes from the Zulu word "ubuntu", translated as humanity, describing the ubuntu philosophy: "I am who I am because of those around me," a positive aspect of community. Ubuntu's goals include providing an up-to-date, stable operating system for the average user, with a strong focus on usability and ease of installation. Ubuntu has been rated as the most popular Linux distribution for the desktop, claiming approximately 30% of desktop Linux installations in 2007.
http://en.wikipedia.org/wiki/Ubuntu
NoteCase is a hierarchical note manager (aka. outliner). It helps you organize your everyday text notes into a single document, with individual notes placed in the tree-like structure (each note can have its sub-notes, ...).
http://notecase.sourceforge.net
OpenOffice.org (OO.o or OOo), commonly known simply as OpenOffice, is a free cross-platform office application suite available for a number of different computer operating systems. It supports the ISO/IEC standard OpenDocument Format (ODF) for data interchange as its default file format, as well as Microsoft Office formats among others. As of November 2008, OpenOffice supports over 45 languages.
http://en.wikipedia.org/wiki/OpenOffice.org
Opera is a web browser and Internet suite developed by the Opera Software company. Opera handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, IRC online chatting, downloading files via BitTorrent, and reading web feeds. Opera is offered free of charge for personal computers and mobile phones, but for other devices it must be paid for.
[url=http://en.wikipedia.org/wiki/Opera_(web_browser]http://en.wikipedia.org/wiki/Opera_(web_browser[/url])
Mozilla Thunderbird is a free, open source, cross-platform e-mail and news client developed by the Mozilla Foundation. The project strategy is modeled after Mozilla Firefox, a project aimed at creating a web browser. On December 7, 2004, version 1.0 was released, and received over 500,000 downloads in its first three days of release (and 1,000,000 in 10 days). As of November 2008, Thunderbird has been downloaded more than 75 million times since 1.0 release.
http://en.wikipedia.org/wiki/Mozilla_Thunderbird
FileZilla Client (also referred to as FileZilla) is a free, open source, cross-platform FTP client. Binaries are available for Windows, Linux, and Mac OS X. It supports FTP, SFTP, and FTPS (FTP over SSL/TLS). As of June 20, 2008, it was the 10th most popular download of all time from SourceForge.net.
http://en.wikipedia.org/wiki/FileZilla
Amarok (pronounced /ˈæməɹɒk/)[2] is a free software music player for Linux or other varieties of Unix. It makes use of core components from the K Desktop Environment, but is released independently of the central KDE release cycle.
[url=http://en.wikipedia.org/wiki/Amarok_(software]http://en.wikipedia.org/wiki/Amarok_(software[/url])
Pidgin (formerly named Gaim) is a multi-platform instant messaging client. The software has limited support for many commonly used instant messaging protocols, allowing the user to log into various different services from one application.
[url=http://en.wikipedia.org/wiki/Pidgin_(software]http://en.wikipedia.org/wiki/Pidgin_(software[/url])
VLC media player is a free software media player written by the VideoLAN project.
VLC is a portable multimedia player, encoder, and streamer supporting many audio and video codecs and file formats as well as DVDs, VCDs, and various streaming protocols. It is able to stream over networks and to transcode multimedia files and save them into various formats. VLC used to stand for VideoLAN Client, but that meaning is now deprecated.[
http://en.wikipedia.org/wiki/VLC_media_player
Skype (IPA: [skaɪp]) is software that allows users to make telephone calls over the Internet. Calls to other users of the service and to free-of-charge numbers are free, while calls to other landlines and mobile phones can be made for a fee. Additional features include instant messaging, file transfer and video conferencing.
http://en.wikipedia.org/wiki/Skype
Wine is a free software application that aims to allow Unix-like computer operating systems on the x86 or x86-64 architecture to execute programs written for Microsoft Windows. Wine also provides a software library known as Winelib against which developers can compile Windows applications to help port them to Unix-like systems.
The name 'Wine' derives from the recursive acronym Wine Is Not an Emulator. While the name sometimes appears in the forms "WINE" and "wine", the project developers have agreed to standardize on the form "Wine"
[url=http://en.wikipedia.org/wiki/Wine_(software]http://en.wikipedia.org/wiki/Wine_(software[/url])
This isn't free, but worth listing:
Cedega (formerly known as WineX) is TransGaming Technologies' proprietary fork of Wine (from when the license of Wine wasn't the LGPL but the X11 license), which is designed specifically for running games written for Microsoft Windows under Linux. As such, its primary focus is implementing the DirectX API.
http://en.wikipedia.org/wiki/Cedega

these items have already been listed, with the exception of ubuntu, which would be a large can of worms we wouldn't really want to open.
not that it's bad, but if you don't know what you're doing, you could end up screwing yourself.
Also, Cedega, only costs a one time payment as far as I know, of five dollars. If you're using Linux it's pretty good!

It is very hard to mess things up with Ubuntu, especially when you can install it without needing to repartition your Windows drive (it can be installed within Windows). Honestly, if you have sufficient knowledge to install and use Windows, Ubuntu is a safe bet for you.
Cedega requires a minimum subscription of 6 months (used to be 3). That's $25. After 6 months, you either have to re-up your subscription for at least another 6 months, or never get any software updates for it again. If it already runs all your games fine, that's no big deal, but if they add support for another game you want after your 6 month subscription is up, you can't get that update.

If you have XP or even vista and want to setup a sharing network for videos or music nothing compares to TVersity. I use it to share my videos with my xbox 360/PS3. You can also use it just for your music library and other internet media.

Updated first post... I left out Ubuntu for now, as this is really about applications, not operating systems... nobody who hasn't heard about Ubuntu before would read about it here and decide to suddenly install it. So It just clutters the list... maybe I'll add a footnote like for non-free software.
About Amarok. Damn fine player... but the Windows version isn't ready for the average user yet, so I'll leave it out for now.
Cedega: I'll add it to the Non-Free section lateron.

I forgot about the Piriform suite of products I use at work. These are:
CCleaner
System cleanup, (Temp files, windows system, program caches, and Registry)
Defraggler
Windows based Defragger, has the option to defrag individual files and directories, along with the entire drive.
Recuva
File recovery.

I like to use the free version of space monger, version 1.40.