Firewall-Kerio Personal Firewall
Antivirus-I like AVG
Intrusion Detection-Snort
Vulnerability Scanner-nessus is the only one I have any experience with
Port Scanning-nmap
Packet Sniffing-TCPDump
Encryption-dont really use any
Spam Blocking-dont use any
Spyware / Adware Blocking or Removal- AdAware and Spybot S & D
Enumeration Tools- Netcat
Other Miscellaneous Tools- There is a little suite of tools called Paketto and it has some really cool/interesting features. Paratrace is particularly neat IMO.