Who's the best?
I've been using Spybot: S&D for ever, but I wanna try other products. So what's the best, S&D, Ad-Aware? Who? :)
Linux.
Or, just don't install Spyware in the first place. Once you get it, it's very diifficult to get rid of. No spyware program will get 100% of it.
Ad-aware is considered the best, according to security professionals
S&D is a close second
Microsoft's is a distant third. I don't recommend it, though, because they only detect spywares whose companies aren't paying them (Gator/Claria, one of the worst spywares out there, isn't detected by Microsoft. And there are others, too.)
Of course, those are pretty arbitrary rankings. I'd suggest having both S&D and Adaware, since neither will find everything.
Adaware finds mostly adware infected files, Spybot finds spyware infected files. Try Spy Sweeper.. it costs money *(cough)* but it works pretty good if you know what you're doing..
I'd agree with iago, don't install it though. After I uninstalled spyware a while back (2-3 months), my computer TOTALLY fucked up and I had to reformat.
I use Ad-Aware SE Personal && M$ Anti-Spyware, just for the real-time protection it provides.