AV-Test recently published test results for leading AV security suites as noted in following link:


QUOTE: Once you settle on your preferred security suite, most likely you’ll stick with it for the long haul. It’s important to choose a tough, effective suite. Researchers at AV-Test evaluated 17 major security suites over a period of 22 months and just published their results as “The Ultimate Endurance Test for Internet Security Suites.” Each suite underwent ten rounds of testing under various Windows versions between January 2011 and October 2012, so in most cases the tests spanned multiple product versions. Bitdefender Internet Security earned the highest score, but others weren’t far behind.