I use Avira (English version), works fine. 

I used to use AVG but it's gone downhill lately and its virus database isn't what it could be, i.e. it missed a trojan on my system.

microsoft security essentials is all you need.

anything but http://www.360.cn/, it is the digital equivalent of TCM. It says its proven, it says all the others are bad and it will flag e.g. any other browser than their own as a security risk. As far as I can tell the 360 Browser is just Internet Explorer wrapped in their own look. .

I would go for AVG or Ad-Aware for free antivirus software, have not had issues with any computers running those

I use avast and spybot search and destroy

Avast rules, using it for many years...

Ccleaner & Malwarebytes anti-malware for regular tuning

All free and kickass.

A cracked Advanced System Optimizer does a good job as well.

A hypodermic needle attached to a saline drip tends to be the cure all for all viruses in China. Not sure about the free bit. Might cost 5 or 10 yuan.

360 is the best by far, but I think it's only in Chinese

use mac... no need antivirus...

I use Unthreat Antivirus and it works well. It's a free antivirus, it doesn't slow down my computer or have any annoying popups. You can check it out here ww.unthreat.com

You previously said you use linux. Since protection against malware is built into every major level of most distros, and the kernel itself, there aren't really many. But the Deb repos list exactly one: clamav, and you mentioned using a deb-based system.

So, there is your answer, clamav. The best is the only option for you. Not saying this was a pointless question that was only part of your insane quest to completely dominate the site through spam but maybe next time "apt-cache search anti-virus".