Ragnarok Online.
PS was a lot of fun in the early beta, until they started with all the "balancing" (read: nerfing a different faction every patch), and broke the netcode so that everyone lagged to hell in a firefight of decent size. Used to be able to do stuff in 40-50 person battles no problem. Then there was a big netcode patch, and I got laggy when there were 5 people on the screen.