I use Spyware Doctor, SpySweeper and Counter Spy. All work for me and all find stuff. If I had to go with only one I would probably choose SpySweeper. All are top rated programs, just be sure to regularly update the definitions. All allow for auto-update and auto sweeping which can be done while you are at work during the day, leaving your gaming and work time free to be productive.
My 2 Kopecks worth.