I like the DarkSide servers, any and all of them have skilled and mature players that will rough you up but at the same time let you die gracefully instead of being kicked/lunged to death. And if you win it's a great honor, until a DS member comes in and kills you
Also JediCouncil [O], but the admins there are sort of abusive of their powers if someone disobeys their spontaneous new rules.
As for Promod, I like Praxeum Knights and Artifex's Official. You can spot alot of Forumgoers there.