I have not used a lot of the programs the others are talking about... but i do know this... Stay away from McAfee, Nortan, or any major AV company that does a lot of corp. stuff. I am not saying they are bad, but they are some of the most used AV programs. When people are trying to write code for a virus they try to find holes and weakness. They're 100s of AV programs out there, so most hacker won't take the time to research all of them to find their weaknesses, they will go after what is used the most. Like I said, i'm not trying to say which is better, but picking an AV that come preinstalled on most new computers (ie dell, hp etc) you are just making yourself a bigger target.