kaspersky internet security which is bundled with lot of tools - - antivirus, antispam, firewall, and many more
I have Kaspersky in all of my PCs and laptops except a new one which came with McAfee installed on it.
I use bitDefendor, but yesterday it told me that I had a virus, but it couldnt do anything about it. I mean, what are you meant to do in a situation like that?
I'm using AVG Anti Virus (free edition) and I also recommend this AV. Use whatever AV you want but the important thing is you should update it regularly to avoid attack from new Viruses.