Potato faces were indeed awful. I've no idea how Bethesda, as a AAA developer, keep messing up their character visuals for their biggest IP
I liked the following bits of Oblivion though:
Thief Guild Final Quests
The Dark Brotherhood
Knight of the Nine
Shivering Isles
Architecture Variety (Would've been nice if the landscape and dungeons had some...)
Music, it was exceptional as expected from Jeremy Soule