Free: Comodo.
Paid: Norton 360.
For the average user, I'd stick with free software. Unless you are one of those people who are either unlucky or run into a lot of sites that are potentially harmful to your computer. Norton 360 is not cheap and is a bloatware, but it does excel very good in all categories. While it does not have the highest score in each categories compared to some other competitors, it does have the best balance and scores at least 80/100 in all categories.