I’ve summarized some tests performed by Av-comparatives.org, an independent AV research company. The ratings are Advanced+, Advanced, Standard and failed (as of Feb 2007)

Results thanks to: http://www.av-comparatives.org/

Advanced+
========
1. Avira
2. eScan
3. F-Secure (yeah!)
4. Gdata
5. Kaspersky (I use this, proud to have blown 300++ on this baby)
6. TrustPort

Advanced
========
1. Avast
2. AVG
3. Bitdefender
4. Fprot
5. Fortinet
6. NORD32
7. Symantec
8. Norman

Standard
========
1. Dr.Web
2. McAfee (hmm..surprisingly)

Failed
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1. Microsoft (not surprising here..)