http://www.javacoolsoftware.com/spywareblaster.html
You do not necessarily need to choose between different spyware removers. They all have their strengths. Most do not run continuously. The remove or disable spyware and shut down.
You need to get the latest updates for any of these tools on a regular basis and run the latest version. Spyware Blaster is particularly cool, because in most cases it will prevent the installation of spyware, not just remove it. Some of these suckers imbed themselves like the Alien into your system. I have seen systems where you had to uninstall Windows networking and reinstall it from scratch.