The best antivirus is us, really.
But we need other protection methods, and this is what I use.
I don't have a single virus in my computer for almost one year
I separate my protection in two different steps:
Immunization and cleaning;
For imunization I use, "Spybot search and destroy" and "Spywareblaster", and a good browser, like firefox, or google chrome. Antivirus I use a free one, Avira antivir, firewall Comodo Firewall, very annoying, but I like it like that!
Cleaning:
Spybot, Malwarebytes, avira antivir, Superantispyware. Ccleaner for crap cleaning, and Defraggler for defragmentation. I think that this is it. Ohh, I use revouninstaller to remove programs.
I hope that I helped!
Just one word about linux and MAC, they are much more prepared for internet, and network than Windows. They are not invulnerable, but more secure than Windows. This is only my point of view