My pick..
I use securepoint for my Firewall and AntiVir Guard for my AV. I do regular "Shields Up" scans on my pc ports. It's a free online scan from GRC.com if I remember, anyway it will give you a status report on your pc ports. If you want to go even further there are rootkit scanners, I got a free one from F-secure, but I think that offer ends in a few days.