Macau is back as the world's top gambling hub and casino companies like Las Vegas Sands are starting to reap the rewards. Macau's gamblers are hitting the tables again and that's proving to be good news for the casinos serving them. The city, the only place in China that allows gambling, has had a tough few years.

The United States. The US is noted as one of the most gambling-centric countries in the world, with a population of over 57 million gamblers. Casinos, horse races, lotteries, and online gambling all have a large following, with an estimated 10 million Americans participating in online gambling regularly.