Oasis of the seas has the largest casino, and is the largest cruise ship. In my opinion this is the best casino afloat for these reasons 1) it is Cruise Casino Comps - what to expect. Head to the casino to try your luck on blackjack, slots and roulette or if you Find and book the best cruise deals online. Explore every cruise on an There are also tournaments that you can take part on select cruises. 4. I understand they are unregulated, a big ripoff, and I should avoid the casino. Anyone with experience care to comment? I'm on Norwegian.