I used to use AVG but since the new version of AVG got bloated, I moved to Avast. Since then, it's been a good move as apparently AVG's new version has been messing people's computers up like crazy.
I first i used AVG. But now i am using NOD32. I have used the old and new AVG. But i didn't really like the new version, because it had a google search thing that gives a 'V' if the site is safe.