Okie so I'm new to these forums and whatnot, but this thread definitely caught my eye. I've worked at best buy for almost 2 years now and have used pretty much all of the major antivirus/antispyware programs + have read and written a few articles on each.
As it stands right now, the absolute best antivirus is Kaspersky. The issue with this is that Kaspersky is Russian to the bone... meaning it is very dominant. It will slow your system a bit and is a bit intrusive towards day to day tasks.
The #1 recommended antivirus is Trend-Micro for its high definition database and behavioral removal capabilities. It's what we use at work on pretty much every computer. It's a lightweight program and with a good system you can continue to play games even while it does a full system scan. (I was doing this earlier today)
Norton, McAfee, CA, Zonealarm, Avast, AVG, etc... these programs are okay for basic day to day use, but if you download a lot or do a ton of surfing, their protection just isn't enough. For gamers, none of these programs are recommended because they slow down the system quite a bit. Also too, the free antivirus that is provided by Comcast/Cox and powered by McAfee is terrible. It simply filters the information coming into the system, but it does not have active scanning or the ability to remove viruses from the system.
As for antispyware, the only real choice out there today is Webroot Spysweeper. It has the largest definition database with support for behavioral detection for spyware, adware, keyloggers, browser hijackers, etc. It's considered one of the best programs for gaming systems as well because of its low impact on the system in a similar way to Trend-Micro.
All in all, my recommendation lies with Webroot Spysweeper and Trend-Micro Antivirus. This is all just based on my experience which you may take as it is, but realize that I've seen roughly 1200-1400 systems in my 2 years of working at best buy alone. In that entire time, I've seen 3 systems with trend-micro and spysweeper loaded onto them that had issues.