First, if you're sick of Adobe Reader bloat, with the huge installer to download, mysterious services running in the background and long, long loading times, then the free Foxit PDF reader is for you. I uninstalled Adobe and bunged this nice light (under 3mb) program onto my machine instead. PDFs open so quickly it's almost like the golden days of Adobe 3 & 4.
Third, OpenOffice 2.4.1 is out. This fully-featured office suite is a large download (around 120 megs), and while it's not all that nippy to start up it's still a pleasure to use. I gave up on MS Office after using the '97 edition for years, and OO does everything I need - you get a word processor, spreadsheet, database, presentation app (similar to Powerpoint) and a DTP program for brochures, flyers, etc.
Finally, if you're looking for an antivirus solution, try AVG 8. There's an unrestricted free edition for personal use, although the first thing I'd do is switch off the safesearch browser plugin, since it's a drain on your bandwidth.
Simon Haynes is the author of the Hal Spacejock and Hal Junior series (Amazon / Smashwords / other formats)