Morrowind was gorgeous. Musically, visually, and from a gameplay and plot perspective, awesome. It was deeper, prettier, and just overall magic.
Oblivion was cliche and overly simplistic. Morrowind didn't require suspension of disbelief, it did it for you. The world is one of the most vividly original and breathtaking I've ever seen. It just felt bigger and more epic.
This tune. This world.
Magic.