I went with Nod32 www.nod32.com There was a PC Magazine article about anti-virus software a while back and they concluded that nod32 had the least performance impact on a system, was at least as effective as the big names, but wasn't the most wizardly, bubble help, user-friendly package.

If you want to do email virus/spam checking on your debian box, have you looked at amavis? I'm pretty sure that it was originally meant to do email virus checking, it's just that spam assassin made it famous.

--Nathan