Independent comparatives of Anti-virus Software
click on the "Comparatives" link on the leftTopTen Review: 2007 Anti-virus Software
These types of comparative testing results will vary depending on who is doing the testing, what they are testing for, what versions of anti-virus software is being tested, etc. There are no universally predefined set of standards/criteria for testing and each test will yield different results. Thus, you need to look for detailed information about how the tests were conducted, the procedures used, and data results.
Choosing an anti-virus is a matter of personal preference, features offered, the amount of resources utilized, how it may affect system performance and what will work best for your system. A particular anti-virus that works well for one person may not work as well for another. You may need to experiment and find the one most suitable for your use. Another factor to consider is whether you want use a paid for
product or free alternative
See BC's Freeware Replacements For Common Commercial Apps
and List of Virus & Malware Resources
Of course, you can always supplement your anti-virus by performing an Online Virus Scan