Windows
AVG Free
This free anti-virus and anti-spyware product is ideal for all home users. For business users, the paid version is competitively priced and provides features to remotely install and monitor over a network.
Spybot – Search and Destroy
A free for personal use anti-spyware and malware software, ideal for cleaning up after problems arise. I now also recommend it as a preventative measure due to an increasing number of problems. There is also a reasonably priced version for businesses.
K-Lite Codec Pack
This is a fast and clean codec pack to make almost any video play in your favourite media player. I recommend the mega pack, which included the Realmedia and Quicktime codecs for those avoiding those comapies bloat- and ad-ware. For those on Windows Vista x64 or Windows 7 x64, I also recommend installing the 64-bit pack.
VLC player
A wonderful simple video and audio player, which is actually quite powerful. It will play almost any video or audio, including incomplete and damaged files.
CD Burner XP
CD/DVD burning software, equivalent to Nero or Roxio. Easy and intuitive to use.
DVD Flick
Video DVD authoring software, allowing for basic editing and also burning to DVDs.
7-Zip
A file archiver that supports many compression formats and offers high compression ratios.
PDF Creator
Creates PDF (also known as Adobe Acrobat) files from almost any program on your computer.
Adobe Reader
A free PDF view created by Adobe.
Adobe Flash Player
Allows the playback of Flash video and use of Flash controls.
Adobe Shockwave Player
Allows the use of Shockwave controls, though these are becoming increasingly rare.
Sun Java
A full Java runtime which enables the use of Java applications and webpages.
Picasa
An easy to use photo editing and organisation software, with several powerful features.
Mac OSX
Linux
Hang on now, isn’t most software for Linux free? Don’t most distros come with repositories full of the stuff, to be installed within a couple of clicks? Maybe I’ll give a few recommendations anyway!