Zenos Character Development >>>>> - Voice work and dialogue is superb.
Everything Elpis / Ancients
All music
Livingway
The Final Day Battle, Pre and Post Cutscenes
Thavnair - Final Days
Jeremy Ang Jones - Voice actor for Fandaniel - Zodiark / Hermes / Asahi / Amon - Deserves mad props for making each of these sound distinct enough and having different personalities.
Flow
Story of course.

All around a fantastic expansion. People really don't grasp how lucky we are to have what we do.