Have you turned on spybot's immunize feature? That alone cut down the number of pop-ups I was getting by 75%. That combined with Shifters link the rest down by over half. Another thing to think about is using a hosts file. Beemer (another member here) has agood one and instructions on how to use it on his site.
I doubt that it is possible to completely stop them all but you sure can stop most of them.!