If the game itself does not take place on the blockchain, then of course the ETH, it is liquid, fast enougth and reliable. If the game takes place on the blockchain, then something faster is needed (this is theoretical reasoning, I do not play such games), something like EOS.
For off-chain gambling, any cryptocurrency works wonders. The real issue lies on Blockchain-based gambling (on-chain) as gamblers are presented with challenges such as high fees and slow transaction confirmation times. Until ETH addresses scalability issues, most gamblers will choose EOS or TRON as their preferred Blockchain network of choice for decentralized gambling. Low fees and blazing-fast transactions is what makes gambling practical on the Blockchain. It's no wonder why many people have been quite fond of cryptocurrencies like DOGE, EOS, and TRON for day-to-day gambling. A cryptocurrency with high scalability, makes profiting from gambling practical.
Nonetheless, there are many cryptocurrencies to choose from each with their unique features and use cases for the mainstream world. Not every crypto is accepted at gambling sites, as it's hard to keep track of each and every one of them. Only those with mainstream adoption will see a higher chance of being accepted as payment method than others. I believe that cryptocurrencies like Dogecoin, Ethereum, Bitcoin, and Litecoin are the most widely accepted coins in the crypto gambling industry. They serve their purpose well for gambling, despite their limitations. Just my opinion