Sumihei has slightly more creative crab cuisine than Bouyourou, and the higher-end rooms are nicer and more spacious, but the onsen is inferior (the chlorine smell was pronounced), if that is important to you.

In Fukui, I'd probably go with Bouyourou, although Awara Onsen Kofu Yuden Beniya is also highly regarded. They serve Echizen-gani (like Bouyourou), although we haven't tried it here. At Yuden Beniya you get to choose to:
- Boil the whole crab.
- Legs served as sashimi, shoulders and shells grilled.

Bettei Zuien in Toyama is an onsen ryokan that's purported to have outstanding Snow Crab - make sure, though, to select the crab plan during booking if you want it.

In Amanohashidate, we've only been to Monjusou Shorotei, which had great crab, but it lacks onsen. A relatively newer property (opened in 2017) might be a better choice there - Amanohashidate Rikyu Hoshi no Oto. It has superb onsen, spacious and contemporary suites, and you can choose to have Taiza-gani for your meal at a 70,000 yen upcharge.

Personally, I prefer more variety than that - I love shabu shabu and steamed crab, too, and like to finish it off with kani zosui (rice porridge.) If you're looking for variety, then Sumihei or Bouyourou would suit you better.

One possibility (and no, we haven't stayed yet) - Tsuruko, a new 4-room ryokan opened in Kanazawa just this past month. It's relatively centrally located - it's within easy walking distance to Kanazawa Castle, although the Higashi Chaya District and Kenrokuen are more like 30 minutes of brisk walking. It should be pretty during Fall foliage season, and Kenrokuen is extremely photogenic in January and February when it's enveloped in snow.

There is a restaurant on site, but guests staying at Tsuruko get meals served in their own room (each of the suites has a counter dining area that resembles the look and feel of the original Tsuruko restaurant itself.) I don't think the cuisine is 95% crab, as is the case with some of the others, but it is a big part of the menu when in season. The executive chef trained at Kitcho in the 80s and 90s for about 12 years, so he ought to know what he's doing.

Just as centrally located is Asadaya. It doesn't have onsen (Tsuruko does, although I don't know if it's piped in directly or brought in by truck and recirculated), and we haven't gone during crab season. But Asadaya's cuisine is renowned, and I don't doubt that they'd offer up a memorable cuisine that includes Kano-gani.

Net-net: If crab is the priority, I'd go with Sumihei. Bouyourou is a close second, and might trump the former if onsen is important to you. We haven't tried them all, though, so if you do choose one of the others, I'd love to hear about it!