ClamAV is working quite well, IMO, but always looking around.
I read how Nod32 is the ONLY antivirus package that has caught every major 'in the wild' virus, 100% as rated by virus bulletin (
www.virusbtn.com - which has some kind of cookie problem, and i can't visit it using firefox).
They have linux versions, but not sure if they have any free version.
http://www.nod32.com/products/products.htmI'm pretty sick and tired of the mainstream antivirus vendors, so this looks interesting.
ClamAV is doing well tho, on the server level, or should i say, the 'SME server' level (via dungog or swerts-knudsen contribs), so no complaints there.