[Crow]

I know a forum with a pretty nice reputation system, and you actually need it there, but I wont explain that further. Not the right place for that here hehe. Though I will explain their system.
Normal users can only give positive reputation. Moderators can also give negative reputation, but only if the users did something that is against the rules. And if someone gives you a positive reputation, you actually see who gave it to you in all the cases.