As bounty hunters its your job to find a good campaign don't just rely on others suggestions you should always have your own way to determine if the project you want to be part is legitimate.
As for my suggestions I create a thread that only list a bounty coins or tokens that only listed in exchange.
Here is the link
https://bitcointalk.org/index.php?topic=5232710.msg54025514#msg54025514thank you for one of the suggestions that you have given I think I have followed the bounty in that thread and indeed for some bounties it was a successful project where until now the project is still running.