No doubts about it that webmastermoney forum is the best forum. One can find minimum spamming on it, except few people repeatedly posting the same thing. This is a sort of self disciplined forum where the mods and the admin are not required to become strict and give lot of infractions.
As long as payments are concerned this is the most honest forum which pays in time. Whereas in MMK and diamondtimes, lot of delays are causing lot of concern in the minds of the members. Both are good forums but they cannot be rated as the best due to delays in payments.