For whatever reason. But list your reasons!
Could be a big smorgasbord of spectator sports (like, Dallas has that, but I don't like Big D in general); or, a lot of great recreational activities and opportunites; or cultural events or historical sites; possibly a good vaiety of great restaurants in all price ranges; perchance a plethora of good-looking women; maybe a relatively low crime rate; or just some very nice, welcoming residents.
Whatever. It's not a scientific survey, just what some folks who also wager on sports might like. (Tho hope we don't get too many name Vegas as their big fave!) Also OK if you live in or near your fave - to be expected.