It has been apparent for some time that the free AVs perform as well as the paid apps, and the latest tests continue to support this. The free AVs from Avast, AVG (essentially an Avast company), Panda, and Microsoft Defender for Win 10 all provided a protection rate of 99.7% or greater against the 754 malicious threats tested over 4 months in 2020.
All the free AVs received the highest rating of "Advanced Plus", except for Panda, which was dropped one rank to "Advanced" rating due to a number of false positives. This despite Panda blocking 99.9% of real world threats.
Meanwhile, at SELabs (the only other independent test site I trust), the free AVs from Avast, AVG, Avira, and Windows Defender for Win 10 all protected against 97% or greater of the 100 threats tested between January-March 2020. All received the highest "AAA" rating. https://selabs.uk/reports/2020/
I have used all the free AVs mentioned here over the years, and can recommend them all as effective. I personally have defaulted to the Windows Defender AV native to Win 10 on all my PCs for its simplicity.
In fairness, I would point out that among all AVs, the paid Kaspersky product has consistently performed best for some years. Concerns have been expressed about using an AV made in Russia. I personally don't worry about that, but see no reason to pay a yearly fee for such a minimal increment of protection.
As always, YMMV.
Dell Forum Member since 2,000
Windows 10 Pro (64- Bit): Malwarebytes 4.x Premium, Windows Defender AV, Windows Firewall, WinPatrol PLUS, Emsisoft Emergency Kit Free and HitmanPro Free (on-demand scanners), OpenDNS, MVPS Hosts file, SpywareBlaster, Pale Moon web browser, Sandboxie, CCleaner Free.
"In the future, everyone will be anonymous for 15 minutes" - Banksy