Trend Micro
After years of relying on Symantec Corporate and Enterprise versions of Antivirus products in corporate/business environments, I am giving serious consideration to moving to Trend Micro's AntiVirus products. We've done some testing with their eval versions and have been quite impressed with their offerings. They offer multilayer A/V protection products including their VirusWall hardware device and even a A/V client for mobile devices (like your smartphone).
Trend Micro Website
Trend Micro Website