(FORTUNE Magazine) – All hail Wegmans! According to our eighth annual survey, the family-run grocer is the best company to work for in America. (For our methodology, see the box on page 97.) The following industries are most heavily represented on our 2005 list: financial services (led by Republic Bancorp), retail (led by Wegmans, of course), and health and medicine (led by Genentech). This year, for the first time, we've divvied the winners into three categories: large, midsized, and small companies. Read on.