I have been looking at different AV programs too. I'm currently using avast! AntiVirus along with AVG Anti-Spyware, Ad-Aware SE, and Spybot - Search & Destroy.
I dont' know much about the stuff, but from the little "research" I've done, I've found the best of the paid programs to be NOD 32, Kaspersky, and BitDefender. They're always ranked in the top 5 or so.
Also look at getting a firewall (Other than Microsoft's) such as ZoneAlarm, if you don't have one already.
Here are a couple of links that I found helpful:www.techsupportforum.comwww.bleepingcomputer.com