Of the generally easily available and free anti-spyware products, I believe that AdAware is the best. In my experience, it catches things that Spybot does not, and it catches them without threatening your operating system.

I have noticed that the AOL native antispyware routine will catch some key counters that the other products will not catch, however. Key loggers that can hide from Spybot and AdAware are an example of the most insidious forms of spyware because they collect and report things like credit card information and bank accounts and passwords.

I doubt that I will ever be able to talk any of you into the efficacy of America Online, however, so I'll just give up right now.