As your question read; the best way to appreciate hardworking affiliates in your team are:
1-: E-Card - There are many e-cards available for the sole purpose of appreciating the hardworking member on your team.
2-: Gift Cards- These are very useful tools for boosting the morale of the active team member.
3-: Team mail- You can appreciate active one through the mail you send to them.
4-: Stream post- It is always good to appreciate them through your home page tab, this will make everybody on the team see those who are really active and also motivate them further.
5-: Re-assigning of PSA- These is best done for affiliates that are participating in any competition set up by you or those that are in your co-op.
