Not sure about the best, but I recommend trying Avast.
360 Security ESET Mobile Security & AntivirusAvira Antivirus SecurityAVL
I know Avast and Avira are good ones but Norton is a clunker. Take a look at this list.
When I worked as an online Tech for a while, I encountered all of these questions at one time or another.
Linux, the most effective proven, updated really often.
Avg free. But used Kaspersky.
since i started using chromebooks a few years ago, i haven't used Antivirus since but if i did have to pick one, it would be Microsoft's Windows Defender and Malwarebytes along side.
There are a few sites with ideas for that. I'll list two for you.
I use AVG Free mostly with Malwarebytes also. I also run Hitman Pro as it's the best second opinion cleaner.