I am of the opinion, that when it is possible...you should definitely avoid free antivirus software because as soon as you install them they will tell you that you should upgrade to the full version to access real security. They are just advertisement schemes and do not offer any competitive detection, cleaning or prevention capabilities. I would recommend doing some research on your own and this should help you determine what AV is the best for your system.
I used both Avast and Bitdefender, I think, Bitdefender is best for Windows 10, Mac and Android devices,
They are providing a 50% BitDefender discount right now !!