The best antivirus is encasing your system in a cement block and dropping it into the Marianas Trench (a space shot into the sun being too expensive!).
Seriously, there are several viewpoints for this.
IMO, the best antivirus is user education. Teaching folks to not click on things that they don't know about.
Reviews (such as this website:
http://www.av-comparatives.org/ ) consistently rank the Internet Security Suites tops for users. But those of us who analyze BSOD's know that they are also the most cranky of programs and that they can cause more problems than most virus'.
I only use MSSE (Microsoft Security Essentials), but many of my tech friends don't even bother with an antivirus. Their thoughts are:
1) They don't do anything that needs security on their PC's (no personal info)
2) They routinely backup their stuff (with images) - so they can restore an image faster than they can remove viruses.
3) They are technical people, so they know the risks when they visit "nasty" websites. They accept an infection as the "price of doing business" on the web.
I had an infection in 1991 that took out the US Army's computers in Saudi Arabia (for Gulf War I). We didn't have antivirus software back then - so we were just a target waiting for the malware to strike us.
Since then I've had 3 infected files on my system - but none were executed, so the system wasn't infected. 2 were caught by the antivirus software - and another was caught by a scan with Lavasoft AdAware several months after it was downloaded.
But I'm different. I'm technically oriented, and I've surfed the web since the late 1980's. I have no problems pulling the plug (literally) if I see something bad going on. I backup my stuff fairly regularly and find it easy to reinstall Windows.
I only recommend using an antivirus (and not an Internet Security application) because (IMO) the Internet Security application only adds a small degree of protection. And I don't feel that that small degree is worth the chance of having a problem with the cranky Internet Security applications.
But despite all the protection in the world, people are going to get infected because of "human engineering" - where people are tempted and can't resist the temptation. What can you do if someone is bound and determined to find out that they're winners of the XXXXX lottery?
Antivirus/Antimalware applications can't easily protect against that!
A while back I had a Social Worker bring in one of their "mentally challanged" clients with a virus infection. The user was searching for pictures of puppies and got infected that way. We cleaned his PC for free and gave him some advice on how to avoid the problems in the future. Haven't seen him since, so we hope that the advice is still working!
