I'm considering purchasing an "anti-spy" program to help me detect if/when there may be hackers, cookies, key stroke programs, or other types of programs that may be in use on my PC tracking my activities without my knowledge.

I've heard Xblock is supposed to be pretty good.

He's more company/program names that came up in my research..... Spector, KeyKey, Snapshotspy, SubSeven, Stealth Keyboard Logger, Surf Spy, Net Spy, GhostKeylogger, Pc Activity Monitor, SpyTech Shadow, PC Spy, STARR, Red Hand Pro.

Does anyone have any recommendations on which is best?
Right now I'm leaning towards Xblock which is only $40.

Any thoughts, and/or feedback on this subject will be appreciated.