Vrap just recommended
Malwarebytes' Anti-Malware to me today and it is both solid and light, though thanks to its malware focus perhaps not as efficient as some of the other full-fledged antiviruses out there.
For sheer disinfection efficiency, I'd have to say that the latest Avast! seems to be the best free scanner out of the bunch, at the very least usability-wise. It does make you register after 30 days though, which is a major turn-off. The other two primary free antiviruses, AVG and Avira (
download links in the post above), are pretty much as they were before.
The very latest Ad-Aware, though, suffers the most bloat and lack of speed. While it's true, like
the company purports, that "Ad-Aware Free now includes anti-virus", you wouldn't really know it. It's also very rude (how difficult can a customized install be made?):
"...the public dissolves as fact and fiction blend, history becomes derealized by media into a happening, science takes its own models as the only accessible reality, cybernetics confronts us with the enigma of artificial intelligence, and technologies project our perceptions to the edge of the receding universe or into the ghostly interstices of matter." - Hassan, Ihab: "
Toward a Concept of Postmodernism" (1987).