Can't answer for Jade Dragon because I don't own it. Holy Fury sounds great so far but waiting for more developer diaries to make a final call.
Legacy of Rome, purely for retinues. Not as useful as they apparently once were, but still can't beat standing armies in usefulness.
Reaper's Due, mainly because diseases get more indepth.
Conclave. Personally, I like it.
Monks and Mystics: The society thing sounds cool, doesn't seem as fleshed out as it could. But hey Satanists
Charlemagne. Go for it purely for the 769 start.
Horse Lords. Only use I got out of it was tributaries, which can be a pain in the ass if you have Charlemagne and play as Wessex in 769
Sunset Invasion because your mileage will really vary on the plausibility of Aztec invaders