I use Ad-Aware & Spybot S&E together.
I installed Spybot on most ppl's comps at work using cain & abel to get a remote shell, mounting a share containing the install file, and then doing a silent installation from the command line (check http://www.safer-networking.org/en/faq/30.html for cli fun). The result is that the users can keep working on their comp without me having to use vnc and take over their kb/m. Then I also set up a couple scheduled tasks which go to 2 different batch files to run spybot in silent mode: one to update, one to scan & remove stuff. Those run once a week on everyone's comp. Unfortunately, Ad-Aware is gui-only, which makes automation impossible, and don't bring up autoit, it's bogus for doing unattended admin stuff.
Be sure to immunize with Spybot, as it will trap any writes to the registry, but disable it when you install/upgrade stuff.
I used Hijackthis to remove a particularly stubborn bit of IE-hijacking Spyware (a browser "helper" object which had run amuck in the registry) from someone's comp at work. It it recommended that you check some forums where ppl are posting their hijackthis logs, it will give you a good idea of what to remove or leave alone.
I installed Firefox on a few ppl's comps, and told them never to use IE ever again. Ever since, whenever I scan those comps with Ad-Aware/Spybot S&E, it shows up NOTHING. Weeks later, NOTHING again. I'm dead serious about not using IE, it is the number one vulnerability to Spyware. I know you don't want a browser war, but a spade's a spade, and to deny it is to stick your head in the sand. Any scatological protests won't change that fact. Anyone defending IE at this point is completely clueless. It's like defending asbestos vs. fiberglass, or defending lead paint.
If you must use IE (some web apps require it), then at least disable activex. But that's not going to protect you--much.
I see you're quite zealously guarding your topic, but haven't you heard of an ounce of prevention being worth a pound of cure? Incredibly, you mention that you want open discussion, yet then you're attacking ppl who are recommending ways to prevent getting spyware in the first place. Maybe you're not interested in avoiding spyware. Maybe you just enjoy removing it. I don't know.