Many technology websites make lists of the top 10 antivirus software programs available, including TechRadar.com and MaximumPC.com. Other websites, such as PCMag.com and TomsGuide.com also provide comprehensive lists, though they are not ranked by top 10.
Each of these websites use various approaches and criteria to find the best software, including testing by independent labs, performance, ease of use and affordability. MaximumPC.com even takes into account the software's "annoyance level."
Overall, these sites found that the best free antivirus software, as of 2015, is Avira, and that the best pay software is Bitdefender. TomsGuide.com and MaximumPC.com also recommend Malwarebytes as a second line of defense against adware and other malware that antivirus programs may not catch.