The Malware Research Group did a recent test on a small number of programs to see how well they cleaned an infected pc.
Allthough this isn`t a widespread test in regards to amounts, etc, it is also good to see what programs fair better.
Results here if you`re interested->
http://malwareresearchgroup.com/?page_id=2
One thing i was surprised by is how SuperAntispyware did, allthough as with tests of this nature, next month could be a differant result...