Just ran across this comprehensive Feature Comparison of popular anti-spyware programs.
As spyware and adware have become increasingly powerful and difficult to remove, developers of anti-spyware programs have added a wider range of functionality to their applications to give users more powerful tools as well as greater control over those tools. Moreover, although anti-spyware applications have long resembled standard anti-virus applications in many way, they have also started to acquire their own distinctive set of features in order to help users deal with the unique problems posed by spyware and adware. Given the bewildering array of programs and features available to users looking for anti-spyware applications, users may find it difficult to usefully compare anti-spyware programs and their feature sets.
Giant Anti-Spyware, which Microsoft just purchased, gets particularly high marks. Unfortunately, the product was pulled from Giant’s Web site as soon as the acquisition becamse official. It’ll be interesting to see what it looks like when it returns in January.