GENENTECH (10,890 employees) South San Francisco From the moment you walk onto the grounds, the Genentech headquarters feels like a bucolic college campus, complete with employees bicycling between the company's buildings. And like any good college, it also has a grand legacy. Rumor has it that the Genentech campus, with its concierge services and its weekly Friday afternoon party, was the inspiration for other employee-friendly companies in the Silicon Valley to start creating workplaces that emphasize fitness and happiness. Genentech is also an innovator when it comes to healthy dining, employing a team of nutritionists who are constantly working to refine the quality and healthiness of the gourmet fare offered to workers each day. AMERICAN SPECIALTY HEALTH (600 employees) San Diego You'd expect that a company known for designing corporate wellness programs would get it right when it comes to a healthy workplace. American Specialty does not disappoint.