The McAfee and Norton versions for home users are terrible. They try to do way too much and usually end up causing more problems than they solve. On the other hand, they do have corporate versions that actually work quite well. I use McAfee Total Protection for my clients. They don't have to deal with any nag screens, and system resources are not drained. If there is a problem I get an email. Before this I would get calls from a client when Norton gave them a pop up to warn about a cookie, and the user would be freaked out over absolutely nothing. We use Symantec corporate edition at the college, and again, no problems. I haven't had to deal with a virus in years, and students are constantly plugging in their flash drives, or connecting their laptops to the network.

The other benefit to these versions is the license management. I don't have to purchase and activate multiple copies of software. Symantec has a management console running on a server, and McAfee TOPS includes centralized management through their servers. At home I use AVG and I have no complaints. Don't forget though, that the free version is only free for personal use.