I'm a big fan of freeware, the reason being quite obvious. It's free. Here are some pieces of free software I like. Add your own. My picks are all for Windows, though many of them are multi-platform.
Office Suites
OpenOffice - OpenOffice is a free office suite released by Sun Microsystems and it is a nice host-based alternative to MS Office.
Thinkfree.com - Thinkfree.com is an online Java based office suite you use through your web browser, including online storage. This makes it simple to access and edit your files from any computer with web access, regardless of platform.
Image Viewers
FastStone Image Viewer - A fast image viewer and management application. It makes thumbnails of your files and stores them in a database, making browsing easy. It also allows you to perform some basic editing tasks, such as cropping and resizing.
Google Picasa - Another image viewing and thumbnailing programme, acquired by Google. I haven't used it much. It doesn't organize your files in a standard directory structure, which is something I had a bit of trouble getting used to, but it seems a pretty solid product. It has a very nice image screen save which zooms in on your pictures, rather than just a standard slideshow. It gives it the feel of a Ken Burns documentary.
Image Editors
The GIMP - The GNU Image Manipulation Programme. This is really the top solution for free image editing. For all of you looking for some way to resize animated gifs, this is the programme to look for.
GIMPshop - GIMPshop is a modification of GIMP to make it's user interface more like Photoshop. This is a good choice if you're a Photoshop user looking for a free replacement.
Security
Avast Antivirus - ALWIL Software offers Avast Antivirus Home edition free to non-commercial users.
a-squared Free - a-squared Free is a dedicated anti-Trojan scanner from EMSI Software. It's a nice addition to your anti-virus software, as the free edition has no resident scanner that can cause conflicts. I run this in addition to my normal anti-virus scans.
a-sqaured HiJackFree is also a handy tool for sniffing out hacking attempts, allowing you to view your processes, network connections, and Autoruns in one place.
Jetico Personal Firewall - The previous version of Jetico Personal Firewall is free. This firewall tends to get the best performance on leak tests, but in order to get the best protection out of it, you need to know what you're doing. For geeks only.
Comodo Personal Firewall - I haven't used this, but I've heard a lot of people say good things about it. I would probably use this over the popular alternative, Zonealarm (which had become very bloated the last time I took it for a spin).
Password Safe - An open source program to allow you to store your passwords in an encrypted database. You can simply double-click on an entry to copy it to your clipboard, then past it into the password field to log in. It also had a handy feature to allow you to automatically generate a random password for any entry, which closes up the big security hole of using the same password for every site. For added security, store your password database on a thumbdrive or other removable drive and so it's not sitting around on your computer when you don't need it.
That's all for now. I'll post more later.