Free Software
Linux
Ubuntu - The best flavour of Linux for beginnersFedora - The most open & free version of Linux
Gentoo - For experienced / hardcore Linux users
Browsers
Mozilla Firefox - The best most configurable web browserGoogle Chrome - The newest and slickest web browser
Opera - Yet another alternative web browser
Photo / Art
GIMP - An excellent Open Source alternative to PhotoshopPaint.Net - Like Paint but supercharged
Inkscape - Open Source vector graphics editor
Messaging
Skype - Instant messenger, video chat and internet phone applicationLive Messenger - Microsoft's instant messaging and web chat solution
Miscellaneous
iTunes - The rocking music library and store, must have for iPodsPicasa - A picture library for your thousands of photos, basic editing too
Google Earth - Map the earth, the heavens and the depths of the oceans
Open office VLC Media Player Audacity WinAmp K-Lite Codec uTorrent LogMeIn TightVNC CDburnerXP ImgBurn 7Zip FileZilla FreeCIV