File Detection Test March 2014
http://www.av-comparatives.org/wp-content/uploads/2014/04/avc_fdt_201403_en.pdf

Real-World Protection Test March 2014
http://www.av-comparatives.org/wp-content/uploads/2014/04/avc_factsheet2014_03.pdf

Comments:

-  The File Detection Tests (formerly called "On-Demand") basically tests an AV scanner's ability to detect malicious files usually obtained from sources other than the internet (such as USB devices and other media).  Most AVs typically have detection rates approaching 100%.  More interesting is the "False Positive" detection rates reported. Avast Free did not fare well in this department, with some 95 FPs this time around. AV-C provides a link to all FPs detected, and it appears related to the latest version of Avast (2014.9.0.2013). Most were reported as Win32:Evo-gen, which is a relatively new heuristic detection of Avast (and probably has been corrected since). Panda Cloud AV Free, and MSE had only 1 FP each.

- The Real-World Protection Test evaluates blocking of malware. A total of 1264 malicious URLs were used. MSE, with an 88.4% protection rate, was used as a baseline for comparison. Panda Cloud AV Free protected against about 99%, and Avast Free 2014 blocked about 98% (both with no FPs). These results rivalled their paid couterparts.

- These results are but a snapshot in time, and may not represent long-term protection/detection rates. But I see nothing here to change my opinion that there are good free AVs out there, and that the average home user need not pay for AV protection.