Oblivion engine, as many people noted, is rather bland - as far as graphical style goes, I consider it the worst of the three post-Daggerfall TES'es. Still, Morroblivion does have its share of things to strike my fancy.
I am using a non-vanilla night skybox and sun glare and a nice mod that makes the fog to be greyish instead of bluish.
I especially like how north West Gash came out. The nights in the new climate may be a bit darker than necessary, but that's why we have Light amulets, Night-eye potions, and, for those advanced in magic, Light spells.