OhioHealth (Columbus). With roots dating back to 1891, OhioHealth has grown over the years to include 11 hospitals, more than 50 ambulatory sites, and 28,000 associates, physicians and volunteers. In 2016, Fortune named OhioHealth to its annual "100 Best Companies to Work For" list for the 10th consecutive year. OhioHealth offers employees a full range benefits and additional perks, such as health and well-being classes for exercise, nutrition and stress management.