I think the OP wanted a freebie AV. Most of the recent ideas are paid for
AVG does appear to be the market leader in the freebie stakes.
You need to be aware that there are differences in the free to paid for products. Most are created in the hope you will upgrade. The biggest must to ensure is that updates are frequent enough to protect you. New viruses are released daily. If you connect to the internet, even just for email, daily, you need a daily update. You might remain lucky but if you do get an infection will the freebie AV software help you to clean up your PC when you have no support?