Webroot
Quote from Tsing Tao:
Eset looks good - but $60 bucks a year? Wow that's expensive.

Quote from blowingup2012:
Just go by PC Magazines top choices:
http://www.pcmag.com/article2/0,2817,2372364,00.asp
Free anti-virus programs will detect and clean out about 80-90% of the infections. If you want to get up in the high 90s then its best to just pay $50 for a year subscription.
The two PC Mag Editors choice antivirus programs are WebRoot and Norton. Norton is the best of the best in detection and cleaning out your system, but it does drag the system and not especially fast. Webroot is almost as good in the detection and cleanout department, but it is very very fast and does not load down the system.
I used free antivirus programs like Microsoft Security Essentials, but then found out my email got hacked somehow through spyware. I decided to go with Webroot and since its installation it has detected a lot of viruses. My system gets scanned each and every morning. The scan only takes a few minutes and does not load down the system.
If I was running a hedge fund and security was the primary concern then I would go with Norton. However, since I dont run a hedge fund then I go with Webroot as speed and performance of my system is a concern.
If you go with either Webroot or Norton then you can go ahead and unload the other firewalls/antivirus programs. Either of those will be better then any free solution and if they cant detect it most probably MSE or other free programs wont be able to either.