Which is the best antivirus?

In my opinion Kaspersky is the best

Webroot, the only program I ever used with Windows. I have a Chromebook now and don't need one.

They all generally do the same job. They all suffer from the problem that they can't detect new malware until its signature is added to the database. Windows Defender is the widest used, so it's the one virus writers like to attack. I prefer Trend Micro Internet Security, but it costs and takes an age to load when you first switch on.

Windows defender