Kaspersky Internet Security 2010 (1-Year License)

Pros: Limited impact upon resources, highly customizable, and good antivirus/internet security package. No reboot required to start the service after it was installed.

Cons: Changes network from Private to Publi" (Vista/Win7). If you have any shared resources (printer, folder, etc.) you have to make the change from Public to Private in Kasperky's firewall. This is buried deep within the Settings.

Summary: Strongly recommend Kaspersky over Norton or McAfee. I would have given it five (5) stars had it not been for the hidden settings change noted previously, and limited documentation to find the fix.