For me webmastermoney is the best forum followed by MMK.
Diamondtimes is also a good forum but I find that they have not yet approved the payments of the members whereas the last date for making payout request was 25th of March. Till yesterday that is after 8 days, it had only approved the payments of just 4 members.
So let us see how fast they are making payments. If they do pay honestly to all the members, then it will also be the best forum.