Thank you for doing this research, it is without a doubt that we know the top #1 cryptocurrency that's being used by the majority of the casinos and that's none other our very own, Bitcoin.
I have to talk about this few coins beca they are very common and you are likely to see them available and being supported by most of the online gambling platforms, they are in the likes of Bitcoin, Ethereum and Litecoin, these three are very common and there's no how you could experience making transactions on casinos without coming across them, but people only like using Litecoin for the purpose of being affordable in terms of transaction fee, it is cheaper to use.
That's true, someone who's into crypto gambling will definitely have to go through with these three if they are starting and if they have been used to the market. What they're going to learn is that they'll probably support or use the native token of that casino if ever they have it.