There really are too many reasonably good AV programs around for anyone but the manufacturers to give very good advice on more than a few. Bundling of other malware/annoyance features in with AV protection also confuses the issues.

A fairly recent (04JAN2006) Security Tests Update gives an idea of the sort of variation in AV detection typical tests find, in this case for several variants of a single virus type of recent interest.

Similar reports come out frequently, and the fact that a given AV program "missed some variants" should not cause a lot of concern. Some programs are consistently nearly always in the 100% category, but there are lots of swaps in position when another different bug is tested. You can look for a program that's consistently in the top category, or feel reasonably secure with one that seldom misses the odd one. The critical thing is to get enough protection without making your machine unusable.

This particular bug is still being "evaluated." The vulnerability is known and a patch released. "Wild" exploits have been rare, and the whole AV industry is still arguing over how much of a threat it is. Positions on the list could change dramatically for the same test rerun a week later, when everyone agrees on what it is.

John