Please stop with the after-hours events!
This is one reason the new Fair Labor Standards Act is going to help a lot of folks get time-and-a-half for that extra time. Or get paid better through a higher requirement in pay for exempt workers. Effective December 1, 2016, it is going to affect all sectors.
I also think it will help end these after-hours events, like the holiday party, or family picnic.
Want to reward your staff? Make the coffee in the break-room free. Order lunch one day a month while they are working. Pay them a bonus, even if it is $25. There are tons of ways that will allow the employee to feel valued without horning in on their personal time.
Oh, and leave the alcohol out of it. Too many ways it can go wrong. Take that money and funnel it back to the staff.