I disagree with all the above assessments.

I believe the best anti virus to be ESET's NOD32.

http://www.eset.com/

They have a fully functional 30 day trial on their website.

It is 58.50 for single user 2 year definitions if you decide to buy. (39 for one year)

I actually purchased this product. That is saying a lot.

It is "available" by other means if you are so inclined. *oink*

A small footprint is a large advantage of NOD32. You don't know that it is there unless you get infected with something, the way an anti virus should be.

My parents are running it on a Pentium 3 700Mhz system with 384MB of RAM. Kaspersky slowed their system to a crawl. They say they don't notice NOD32 running.

Heres a comparison page I found on their site.

http://www.eset.com/products/compare.php