I have tried numerous anti viruses and I find the best one for me is Microsoft Security systems - It is updated requarly and it is Free - alvailable for all windows platforms
Just pick one of them and try by yourself. I haven't tried Microsoft Security Essentials, they are relatively new comparing to Avast which have been around for ages.
Avira. It's free. It's available for both PC and Mac. Check 'em out here: http://www.avira.com/en/avira-free-antivirus
I used Quick Heal Anti Virus which is good and protect your computer from various viruses. Most of people used it.
The best anti virus is common sense. Avoid sites that you are unfamiliar with. Stay off of questionable sites, and avoid clicking on links as many of them are a one way ticket to virus land. I have a couple of dozen sites that I frequent for work related purposes. I had them all checked out for safety. I do this in advance *before* I go to a new site. It is time consuming to do this, but for me it's worth it. I had a PC destroyed by viruses once, never again.
Eset Smart Security (nod 32) ALL THE WAY! I've been using it for more than 5 years now and never had any problems with viruses.
I find that avast is the best free one out there. It will get the job done for you and block almost every virus without fail. Check it out.
AVG is pretty good. But whatever you do, NEVER buy Norton. I've found them to be an absolute waste of money and they catch stuff less than AVG does.
I agree, and also Norton's anti virus protection is so strict that it will prevent you from accessing some sites. I stopped using Norton years ago.
I share your opinion @Spoiltdiva , I recommend exactly what she said, she's touching the sensitive point. In addition to that, you may use Linux distribution and avoid any kind of virus or malwares, most of virus are designed to work on windows not the linux, it is my best solution for the security!
Norton Antivirus and especially Norton Internet Security 2013 versions are almost near Avast for lightness and top3 of the best security. Just try the trial and i am very sure that you will buy it.