iClassic because Graal-style Graal is the best, Xor has always been fair and responsive for anything I've ever needed assistance with, and the higher-ups in the staff chain like Rufus, Dusty, and FP4 are the smartest so the server generally has the best direction

Downside is the pessimistic player community, but I can't be certain that other servers aren't that same way because I've yet to play them enough