I use and like Webroot, it can be a lil anal at times though such as not letting some programs normally just online games from working. Making you go into the fire wall and fix it so they can be used, but it comes with some cool stuff like cleanup, a better verson of disk cleanup to me.
It also lets you back up your files online as well, but I suggest you just google a search for the top 10 antivirus programs. I do suggest you stay away from nortan, that program is very annoying to every one I know who has it as well as me.