The Witcher, I heard it is pretty good.
Two Worlds is kinda cool but alot of people didn't like it.
Minecraft, kinda an rpg but there is no leveling, story, quests, or even ally npcs.
Maybe some mmo rpgs?
WOW is cool
Eve online is a unique game
Star Wars Galaxies is old but very fun
The witcher is excellent IMO but really need more input by the OP.
For instance, games like dragon age and mass effect are two difference feeling games both by bioware.
Titan quest in an oldie but a goodie. A first person one would be dark messiah might and magic, then their is the gothic series. Plenty around but everyone likes different things.