JoshDM's Journal: What Free Applications should I load to a Windows PC?

As a computer programmer, I've been tasked by my family to "fix" their computers. The one swamped with virii from browsing the wrong websites, the one with the legit copy of Windows that failed Windows Genuine Advantage, the one who never upgraded his o/s but wants "the wireless", etc. The Tweaking Companion has been an invaluable tool to me, and after any cleanup and upgrades (software and firmware), and any user-specific requests, I give my users Firefox with Adblock Plus (Google Chrome is also an option), and OpenOffice if they don't already use a MS Office suite. Now we have clean and working computers, are there any other applications I should be installing, or tasks I should follow?

I'm asking about free (non-shareware), legal applications, entertaining, useful, and non-complicated. Moving them off Windows is not an option.

Media and education

[tqft]

Vlc is my favorite player
CDEX has always given me good vibes on Windows if they want to rip stuff for their ipod
http://cdexos.sourceforge.net/ [sourceforge.net]

celestia for deep sky adventures & stellarium for ground based observing
http://www.shatters.net/celestia/ [shatters.net]
http://www.stellarium.org/ [stellarium.org]