Spy Sweeper
Chrome's sandboxing would be sufficient protection from anything but a trojan, I would think. And Chrome at least has an adblock equivalent, but every time I try to give it a shot as my primary browser, I get tired of struggling with the awful UI after about 15 minutes and go back to Firefox. Shame really, since Chrome - the program itself - is quite excellently done, and very fast (although not much difference with the new version of Firefox now, not sure about IE9)
