In order to place bets on these betting sites with sign-up bonuses, you must be in a state in which sports betting is regulated and where the corresponding sportsbook has a sports betting license. In the table above, you'll find our top-rated sportsbooks and welcome offers, complete with promo codes and links so you can sign up for one of the best betting sites in the US right from this page. We've done the research for you, looking at every factor (including competitive odds, welcome offers and promo codes, mobile apps, and more) to give you a rundown of the best betting sites in the US. As online sports betting becomes more prevalent, it can be daunting to choose among the dozens of sportsbooks in the US.