Hi Amsa,
To celebrate your 10th-year completion - annual day, you could try following things like:
1. Book a Hall for a day's celebration.
2. Invite a Guest (businessmen, CEOs of other companies, Entrepreneurs).
3. Arrange for a Guest lecture (30 mins).
4. Annual Day report by admin, HR, or CEO of that company (30 mins).
5. Invite a celebrity.
6. Celebrity speech, performance (30 mins).
7. Award distribution for best performers (star of the month, employee of the year, best team, best team lead).
8. You can invite the employees' families to take part. They can be introduced to one another, which can be an icebreaker among employees and a healthy way of networking too.
9. Arrange for games (at least 5 to 10 games, you can get the help of event managers) - Divide the employees into teams - While they participate, their families can be the audience to motivate them.
10. Arrange for excellent lunch/dinner.
11. Arrange for a dance floor for the employees, (you can also arrange for an external dance school to give a performance or mimicry artist's performance, something like that... creative enough).
12. Common gifts/memorandums to all employees.
13. Arrange for a quick talk of each employee about their previous year experience, success, the best thing they felt at your company.
14. The next year goal announcement.
Hope this will help you to some extent. If it is helpful, do let me know.
Thanks,
L :)