AVG Free

   A good basic anti-virus program but it should be supplemented with other tools such as SUPERAntiSpyware or Malwarebytes'

AVG Pro

A complete anti-virus protection program from E-Mail scanner to anti-spyware (2 year license)

Norton Antivirus

Basic anti-virus protection program but with the  added benefit of Symantec security.

Norton Systemworks

Norton's complete system coverage program.

Avast! Home Edition

A free but powerful anti-virus protection program, should be supplemented with other tools.

MacAfee

MacAfee complete virus protection. Effective and simple.

ZoneAlarm Pro

ZoneAlarm Pro. Security guaranteed by one of the best firewalls offered.