I like Morrowind's feel over Oblivion's. Morrowind has a better world, Imperials and Cyrodiil, are too, standard. However, Oblivion dosen't have any gore from enemies, and for the props, I modded them to be skeletal, so I prefer Oblivion, for that reason ONLY!

EDIT: Why, you ask? I have an irrational fear of blood...