Another vote for Avast, and one for Microsoft Security Essentials!
The great feature of MS Security Essentials is that it is licensed for use by Businesses!
Last time I checked, it was the ONLY AV software legal for use by businesses...
I use the AVAST on my secondary notebook which is for afterhours surfing and it does quite well too... but right on it's page it says 'Free For Home Use'.
Either is a good choice for your AV / AM strategy! If you want to validate your current strategy, try my eBook... Might help you out, or may just validate that what you are doing is right on...
HTH...
Patrick