it depends what kind you like but my favorite is guild wars it like a upgraded version of WoW exept there are a lot of diffrences between them the biggest one is that guild wars is actualy good as WoW is bad
I think they can have good points about them. I especially like AQWorlds. The Artix Entertainment series is very structurally sound, and hacks fail quickly because AE is AWESOME! (my opinions, i know, no need to point that out)
My favourite: Lineage (not II, the first lineage) best PvP in all mmorpg's existing. Graphics aren't awesome, it's normal, it was one of the first MMORPG in world, but anyway, it's still purely awesome.
But the rest s*ck some. Example is Flyff, I leveled to 54 in like 4 days doing advance party and taking XP (the other ppl gain more XP if you're with them).
It depends on which ones you play. Some are more competitive than others. Most Asian-made MMOs are based more on the social aspects. Then again I am a fan of almost all MMOs.