GOTHIC 2
I'm glad you brought this up, while agree there are several good rpgs out there such as diablo or fallout, there is this game few americans are aware of, but which is massive in europe. I myself was not aware of this. I saw this game called Gothic 2 sitting in the store shelf for several months, until finally one day I bought it. At first I was put off by the rather unique control scheme, and a bit more difficult combat than Morrowind, but then... WOW! After playing this game I can say morrowind has NOTHING on it. Gothic 2 has everything: fantastic comabat, sounds and music, gorgeous visuals, characters and npcs, and a good plot. One of the best features is the combat system, it is not simple point-and-click-and-forget-everything-else morrowind style combat. Combat success depends in large part on your "own" fighting skill instead of just stats. So even as a low character you can dare to take on much more powerdul enemies. Think of it as sort of playing Street Fighter in an rpg. But the thing about the Gothic games is there is an awesome vibe and feel to the game, with all the elements coming together. For instance the whole world breathes and is alive and real, unlike the worlds and characters in morrowind and kotor. Every line of dialogue is spoken.
If you visit gothic 1/2 related forums you will find that the gothic fans are almost religious fanatics, and almost every fan of gothic says it is the best rpg ever made. Even morrowind fans who have not played gothic comment on how huge fanatics the gothic fans seem to be.
Trust me, try gothic 2, chances are you'll love it. And have you looked at the screens of the upcoming gothic 3? It should be released sometime in spring 2006, and the screenshots are even more awesome than the oblivion screenshots.