I can't speak for others, but personally, whilst I find combat and other gameplay animations to be great, facial animations on NPCs are definately what I would call stiff. Huge uncanny valley effect, with realistic mouth and eye animations but without enough deformation in the cheeks, nose and forehead to adequately sell it. They look like animatronic robots with rubber skin.
I agree with this, but I would add that the eyes too are always open the same about. Eyebrows would raise, but the eyes wouldn't widen. I think if they push the wholw brow area a bit more it would make the faces feel a bit more natural.
I'll also add that the animations don't transition into each other as smoothly as they could, giving a little jerk between them and lending the npcs to a more animatronic feel.
In the end it's just semantics, but when the game looks this good, it's hard not to notice something's a bit off.