Im using the AVG 2013 one. If downloading its a Trial but search on google to get it Permanent. its free and really easy. I could give you a activation code if you PM me.
But AVG 2013 is the best for me, i tryed alot. People always told me to use Avast but that one eveytime gives me errors or stupid things. I stick with AVG.
AVG isn't that good at blocking everything and I have past experiences where it failed to detect newer types of malicious programs. Comodo would be a better choice. But right now Kaspersky does the better job of protecting my computer.