FanDuel and Caesars are my two highest-rated sportsbooks, and they're nearly neck and neck.
FanDuel edges ahead with better overall odds and a wider selection of prop bets, plus it packs more features. What's more, I slightly prefer FanDuel for live betting because they offer live Same Game Parlays. However, when it comes to live football, I tend to use Caesars more because of their Watch & Bet streaming platform.
Caesars features a simpler user interface, bigger welcome bonus, more promotions and odds boosts, and sometimes offers better odds for certain markets than FanDuel. Moreover, Caesars has an industry-leading loyalty program, while FanDuel doesn't offer a loyalty program at all.
Regardless of which of these sportsbooks you prefer, it's smart to use both since they often provide the best odds and player incentives on the market.
The tool below will detail the specific areas where each sportsbook has the advantage.

