Don't be misled by the advertised "percent return". You'll take home far less than you think. This happens because people don't pocket their winnings; they put them back in the machines. It's called churning and it takes a toll on your bankroll. Instead use the actual "percent hole", a far better predictor of the results you can expect. So bet smart and be aware.
Just select your game and plug in the bet amount and it automatically calculates the house advantage that's built into every bet and the actual percentage hold based on the churn rate - giving you an idea of how much of your original amount you can plan on taking home with you.