I think a new god pledge with the two main boxes would probably sell really well.
I see Hera, Poseidon, Hephaistos as the core expansions; their availability should be a priority, probably followed by Titans.
Trojan War, Oedipus&Sphinx, Manticore, Hell Judges, Echidna's Children are all good and well, but not really required for play. (I say that as somebody who didn't get them all.)
I cannot tell about Corinthia/Ketos.
The Books - where there ever PDF versions? If not, and if you want to do right by earlier backers, offer a PDF of each item as well this time around and give it to the people who got the books during the first KS for free.
Thermopylae: I think it was a mistake to put water on the back; that should have been the rock pools. Maybe do that.
Terrain Set, Dice, Clips, ... I think they'd sell.
If you had stuff up the sleeve that wasn't unlocked during the KS and could quickly be produced, go for it, put it out there.