The best servers I've been on:
Plant's Space RPs.
Jax Firebus's server USED to be good.
Gcat's Government vs. Rebels pre-v21.
Cysero's Medieval RP before everyone decided to do nothing.
Wicked's CityRPG.
Aeschylus's ParadiseRP.
Right now, the best server is Tezuni's Jail RP in my opinion.