I personally hate norton and mcafee. No matter what I do, it always seems to slow down pcs I worked on. I used both kaspersky and microsh!t security esstentials and both seemed to be pretty good. Kaspersky have been ranked number for awhile , but now there seems to be several that are ranked together at same level, with different personalities.
bulldog is another alternative that I have used, I used it during the win7 beta trail, didnt like it, but got the final registered version that is better. I seem to prefer the kaspersky and MS security essentials.