Vegas and Atlantic City have cornered the market on casinos, somewhat unfairly. There are numerous casinos dotted throughout the United States, many of which are breathtaking, versatile, and located in cities with more to offer. Plenty of them are just as luxurious as anything you can find in Sin City, plus you get to play in a quieter, more low-key atmosphere, which can increase your enjoyment tenfold. Niagara Falls Is a Double-Threat Image via Flickr by David Flores Folks throng to Niagara Falls to see the falls themselves, to climb aboard a boat and float right through them, and to…