My list of freewares that I install on every computer I own is
1.
AVG Free Version - free antivirus
2.
Superantispyware - spyware
3.
PCTools Firewall Plus - firewall with lots of customizations
4.
Textpad - an advanced notepad with a block select mode
5.
7-zip - a nice archiver handling both zip and rar formats
6.
K-Lite Mega codec pack - plays virtually any kind of AV file
7.
Google toolbar - for quick access to wikipedia and numerous other search engines. Also as popup blocker
8.
Google Earth - no need to mention why
9.
Yahoo Messenger - for voice chat and internet telephony