The Security Mentor

To make matters worse, some scumbags (that's a technical term, folks) have been using product names and web addresses confusingly close to those of legitimate anti-spyware products.

Legitimate products and web sites:

Ad-aware comes from lavasoftusa.com.

Spybot S&D is currently at safernetworking.com. I think Spybot's interface is a little quirky, so by all means check out the tutorial.

If you see an ad for some other removal product, Google for reviews and see if anyone reputable recommends it.