You know what the biggest appreciation for an employee is? It’s not a title, not a good review, and not even a salary raise.
The best appreciation comes when your old teammates or managers call you to join them at their new company. When there are no company rules involved, no need to be nice just to keep good work relationships—when your former manager needs to hire someone and remembers you, decides to message or call you to join their new team.
This is the highest appreciation you can get. When someone chooses you not because they have to, but because they want to work with you again.