Which anti-virus do you use?

I have been using McAfee anti-virus for the past year and have been quite satisfied with it, although I am considering getting the much talked about AVG anti-virus software from Grisoft, which is said to be better and is absolutely free. I know of some people who use it along with Norton or McAfee, but I believe that can cause some complications. I found that the best place to download AVG's free anti-virus is CNET's Download.com, which has all the free software downloads listed. It's my new favorite site, and I will be getting a better spyware blocker as well as a break reminder tool, so I don't end up working too long without a break.