I've been kind of forcing my way through Valhalla. It's not bad but it's not really gripping me that much. It has a few great moments but it doesn't feel like it sustains the momentum.
One of the issues may be that you have several other games that do a very similar setting (think medieval fantasy) so the location and atmosphere isn't "new."
Of the three being discussed here, I preferred Odyssey over Origins and I'm undecided between Origins and Valhalla, need to finish Valhalla first. Origins looked amazing and had a great setting but the story didn't really pull me in and there was a lot of "why would you do/think that" moments from the protagonist. Odyssey I played as Kassandra and I think that was the correct choice. It for sure gets repetitive but I think the setting and some of the islands really had some great stuff there.