I use Avira. It has a long history of reliability in blocking malware. I look up the statics of real time protection and performance impact at
AV Comparatives. I went with Avira as they offered a no nonsense free version. Now I use the paid version for most of my computers. My seldom used computers have been switched from the free Avira to Windows Defender. As they started adding nonsense to their free version. By nonsense I mean junk like "Software Updater" and "Phantom VPN" to someones Antivirus install.
It's a shame Avira started adding the junk to their free version. That's why I left Avast. That also means whenever a client asks which antivirus to use. I no longer recommend Avira. Most of those people I had recommended the free Avira to in the past upgraded to the paid version.
When it comes to protection. Windows Defender has made some huge strides in the last couple years. It used to be little better than an open gate. Now it protects just as well as any other anti-virus. I haven't switched all my computers yet because I still have four years left on my five year/five computer Avira Pro license. Windows Defender does have some caveats. It has a high false positive count. So, you may be overly alarmed that a virus tried to get into your computer when it was something benign. Also it has a higher impact on performance than most other options. Although that is largely mitigated if you use an SSD. There is also the concern that MS will backslide on protection quality as Defender has such a poor track record.
As it stands. If you want paid. Get Avira. If you want free use Defender. Your ISP may offer Symantec or McAfee with your internet service for free. Many ISPs do so.
Keep in mind you should have a secondary scanner. By secondary scanner I mean something which does not provide active protection. You never want to run two anti-viruses at the same time. Malwarebytes is the best. Manual scans are quick, especially on SSD. It is extremely effective at removing infections. There is no need for the pro version. I also disable the options to start with Windows and the 14-Day trial. Mostly it will find potentially unwanted programs in your browsing history. Which are probably trackers.