Me personally, I would've liked some huge monsterous beasts. Something that felt epic fighting against and beating. Something like Final Fantasy XII, with the Behemoth King, Yiazmat and the other various wyrm enemies. There really weren't any unique enemies/monsters in Skyrim. Even the dragons, they all seem exactly the same. Even the couple of dragons in Dragon Age: Origins were epic battles and you felt accomplished after beating them, but not so much here.
Also wouldn't have minded some goblins. Yeah, we have the Rieklings, which are basically goblins, but not exactly. And they aren't even challenging.