My recommendation is to never serve alcohol at a company party. There's simply too many negatives that can happen - and they override the positives. From companies I've worked for to companies I consult with, I've personally seen the following:
- A 25-year employee left a party, ran into a telephone pole, was convicted of DUI, and subsequently terminated.
- Another long-time employee left the party (which took place at the business), and as he was driving out of the parking lot, side-swiped two cars belonging to co-workers. A lawsuit was initiated, and the employee left the company.
- Two sexual harassment lawsuits were filed (before I started consulting for the business) stemming from too much booze at the party. (Remember, sexual harassment does not need to be on company premises - if they're employees in a work situation - like a company party - that's enough).
One final piece of advice if you consume alcohol at a company party: I've never seen a career made as the result of behavior at the party, but I've seen plenty of careers ended.