A simple list indexed by country name and name of the casino on wikipedia. Who wants to help?
Being an active user of Wikipedia, I would say that it is not possible to create such an article there. Such a list will be immediately flagged as "promotion" or "advertising" and after reviewing by the admins it will be deleted. Hence I would say that there is no use in spending our precious time in creating such an article or even a sub-section of an existing article.
I think it should not be like that. We should have information about the best casinos that accept Bitcoin around the world. This should be on Wikipedia because so many people use Wikipedia and they should know about such things. Google also helps you find such casinos. One could also compile the list of famous Bitcoin casinos and upload it their websites which might help others. If you do that for the leading crypto casinos, it would not be counted as advertisements or promotion as they already got users.