Gothic amazed me, i got it like 2 years late because it's one of those overlooked games, but i must say it absolutely beat NWN (single player) and i enjoyed it alot more than Morrowind (morrowind had terrible fighting and lacked -real- NPC interaction). Gothic2
should be out real soon (end of the month i believe)...well the english version..if you're german i guess you played it last year already.

Then there's another sleeper which i find kind of charming, Arx Fatalis. If you remotely liked the Thief series and RPGs you'll prolly enjoy it too. It's very linear though (and 3D) but have a unique playing style for an RPG.