Eugene's observations

Following my annual review of reviews the consensus of the most recommended products this year is (again) BitDefender Internet Security. Runners up are Trend Micro, F-Secure, Norton & Kaspersky.

For low value systems the best free product is Avast, although it does not offer the same level of protection as any of the above paid products. Note that the Windows Defender (nee Security Essentials) is included in Windows 8 but performs less well than any of the above.

What makes BitDefender the best you may ask: the comparisons included impact on system performance, ease of use & configurability, detection rate for existing and zero day infections, false alarm rate, additional features and cost.

I will be buying BitDefender licenses wholesale and am happy to offer them at a much reduced cost compared to the producer's own website.

For Apple Macintosh (OS X) users I recommend Avast or ClamXav.  It is available free from the app store.