Go with SpywareBlaster
From Javacool Software : SpywareBlaster doesn't scan for and clean spyware--it prevents it from being installed in the first place. SpywareBlaster prevents the installation of ActiveX-based spyware, adware, dialers, browser hijackers, and other potentially unwanted programs. It can also block spyware/tracking cookies in IE, Mozilla Firefox, Netscape, and many other browsers, and restrict the actions of spyware/ad/tracking sites.