I work in I/T. 90% of my job is removing trojans and adware/spyware. I use AVG Free, Mawarebytes Anti-Malware, ComboFix, Ccleaner and Spybot Search and Destroy. I charge people way less than any chain places. I will clean a machine for $40.00. If most people would just search the net, they would see they can fix it themselves.
As far as Mac goes, I think they might make a good night light or something. I personally will never own one.