Have to go with Bit Defender on this one. I combine it with Windows built in security.

The answer would be a UNIX based OS

Just Malwarebytes.

ESET Smart Security 6

I voted for other because :

Windows is good enough if you search safely.

Otherwise, i'm using Bitdefender, but I'm looking for EsetNode and Emsisoft, both really good.

I use Avast Free for years. It was good. I just stop using it.. I was not able to renew the free version, the free renewal option looked like disabled to me and showed me premium trial and loyalty discount screen. Not to mention, it always notify me to upgrade to premium version. Now I use Kaspersky Internet Security. I use Kaspersky before using Avast, so it's time to go back to my old favorite.

When I made the jump to Lubuntu from Windows I've not had to run any antivirus applications, there are options available yes such as Comodo but I don't see any need to install it, overall Linux is a very secure environment in my opinion.

Eset Nod32 Antivirus 10 is the cleanest and most efficient antivirus.

Windows Defender comes pre-installed and is great so why bother

i use kaspersky since im in Online... so i would say about 10 years or so?