Neverwinter Nights works alright in co-operative mode. It's what the game is about! Beyond Divinity could do the same. Of course you have to play with someone you trust and can rely on.
RPG competative games don't work because not all characters are designed for combat. A lone Rouge or Cleric is easy pickings versus a Barbarian or Wizard. One multiplayer "RPG" that was alright was Necromania. I don't know if it was ever released, but I played the demo. The game was essentially Spy vs Spy (if you remember that one!) with six unique players. You had to find the keys to get to the exit. The keys are hidden about the map in logs, chests, behind other locked doors, etc. There's only one of each key, so you need to kill who ever has it to get it! You can booby trap hiding places and anywhere on the ground. Each round earns you experience which you can spend on Combat, Armour, Mana and Speed. I can't remember if you could buy skills too. And just for the hell of it, the game was M rated with things like the skeleton cackling "DIE, MOTHER ******!" There's about 16 demonic characters to choose from, each with their own special abilities. I wouldn't mind getting it if I ever saw it, even if I don't play multiplayer.