I bought the Dixit Odyssey standalone base game and was wondering which expansions would best match up. I want to keep the expansion by the same artist (So not Journey). I also want the cards as abstract as possible. I do not want to purchase the original Dixit as I have forked out extra money for the Odyssey base game, I just want the best expansion. Any advice would be hugely helpful.
When it comes to the differences between various Dixit games, I'm hoping you've already read this question (and its answers).
But to answer your question, I'm not sure there are really that many choices to make. Dixit 1, 2 and 3 are meant to provide similar experiences but with different cards, so there's no real difference there in terms of abstraction or complexity. They are each equally apart from the Oddyssey game. And maybe I haven't noticed the way to do it, but once the cards are shuffled together, you can't really tell the decks apart. (truth be told, I haven't really tried it. The more cards, the merrier)
The only real choice is between those three expansions, and Journey. Sadly I haven't played Journey but I've read it feels similar to Odyssey (so I'm guessing less abstract, but that's speculation on my part).
Some people advise you to look at the cards of each expansion so you can decide which one to purchase. To me that always felt like spoiling on the fun. I've never browsed through the decks, not even once, and on very rare occasions I still get cards in my hand that I thought I'd never seen before.