Two things I really like about this the most:
1. Providing your employees with healthy, freshly cooked meals on-site! A decent cafeteria that actually provides fresh meals is a heavenly gift and beats ordering and take-away pretty much all the time, both in quality and price so if you can pull it off, by all means provide that for your employees! If I was to switch jobs, a good cafeteria has become a must for me now and it would actually be a factor holding me back.
2. Eating together, focus on "family" in the office. At the IT company I used to work for, we had a small kitchen and a huge table for everyone and very often we would end up eating lunch together, cooked by us or just ordered pizza/kebaps, and we would crack open a beer in the evening, we would play DotA over the LAN in the office until late at night, we would have a movies night, we'd celebrate successes and our xmas party in the office quite often and if an employee wanted to, they could even use the office for a private party with close friends or have their pen+paper rounds there because the table was really damn amazing and the location was right downtown, easy to reach for everyone. What this came down to: this office was way more than just an office; it was a place were we worked and were you also spent countless amazing and fun hours as well. Without failure every time I stepped into that office, I felt a bit "at home" away from home and it was just always a great, relaxed atmosphere and everyone just loved being in the office because you instantly associated it with more than just work.
Emphasizing and acting on the simple idea that the office should be more than just a boring 9-5 work place, more than just a regular office, was definitely one of the best things our boss did there.