I use Firefox and Thunderbird for web browsing and email.
I was also using Microsoft Antipyware Beta but have removed that for the moment since it hadn't found anything for months......ever since I started using NOD32 in fact.Adaware and Spybot always come up clean too.
AVG free, MS Antispy although I have not scanned for 3 weeks and no firewall for 4 years + a lot of common sense. If you have no common sense no amount of AVs' or firewalls will help you. I never have any problems.
Avast 4 (free) Zone Alarm (free - btw recap ZA Pro is not free) Spybot S & D NAT & SPI firewall built into D-Link wireless router WPA encryption in D-Link wireless router Firefox & Thunderbird common sense