I've been running AVG on my system for about a year now, and haven't had a virus in that time (*knock knock*). Of course, it's hard to say that it's because of the software, and might just be my online behaviour, but I do know it's caught a few since I've had it installed.

All I know is that Norton and McAfee wish they made programs that were as clean and easy to run as AVG. Norton is practically adware, and I've never gotten a clean uninstall from them.

And it's just hard to turn down a free program like that.