So I think I'm gonna play Oblivion or Morrowind for a little bit

Well since you played Risen you might know the predecessor gothic trilogy already, but in case you don't gothic 1 and 2 are the best games i've ever played. Gothic 3 was not as good because of many issues but i hear the community has come up with many patches that fixes them. My suggestion would be to try the first one to get a feeling of the game and then play the second one which is a masterpiece.