Hi,
Apart from what u have listed you can do following
1. Best suggestion award- In this suggestion can be taken from employees on particular topic related to company such as cost reduction and the best suggestion should be rewarded ( need not be a monetary reward.
2 may be a Kaizan type- On a particular format from each employee the inforamtion should be taken as how a particular act of theirs have helped there dept, or a colleague or company. Best of out of that can be put on the notice board. This can be a monthly activity.
3.There can be a movie day quarterly , half yearly or yearly depending on strength of employees.
4.You can have a talk or presentation on awareness of diseases like Aids, cancer etc as all may not aware of it in detail depending on type of employees.
Regards,
Harshad