I'm not using any AV for like a decade. Cheap router is my firewall. Common sense is my "threat prevention".

I cannot stand most AV vendors everything about the software seems untrustworthy, AVG and AVAST. I don't trust them really, they seem bloated and phony. I use Malwarebytes, which was already suggested and I also use SuperAntiSpyware. I also try to watch what websites I am on, and what I download, basically just common sense like someone else has stated. I haven't encountered anything major that I could not remove, I did get have a insanely bad piece of adware/spyware that affected my browsers maybe a year ago that I had to do a system restore, probably was the most annoying piece of adware I have encountered.

I don't use my windows machine very often anymore, but I use Microsoft Security Essentials and Malwarebytes: https://www.malwarebytes.org which seem to compliment each other pretty decently, and neither ever seem to get in the way.

ClamWin if I find myself in a position where this is my problem.

The researchers at the AV companies all talk to each other. Every AV does a pretty similar detection job. So the difference are PITA factor.

Try Comodo Internet Security, it's free and it does not bother you or just FREE yourself from the Matrix(Windows) and switch to the real world(Linux).

You don't need AV software.