Best payout slot machines are those that offer higher return-to-player (RTP) percentages, typically ranging from 95% to 98%. These machines are designed to give players a better chance of winning over time, making them popular choices in casinos. Look for progressive jackpots and high volatility slots, as they often provide substantial payouts. Additionally, players should consider the machine's gameplay features, such as bonus rounds and free spins, which can enhance the overall experience and increase potential winnings. Always remember to play responsibly and set a budget before spinning the reels.