Best paying online slots are games that offer high return-to-player (RTP) percentages, often exceeding 95%. These slots attract players with their potential for significant payouts and engaging themes. Popular titles like "Mega Moolah" and "Gonzo's Quest" are renowned for their lucrative jackpots and bonus features. Players should look for slots with high volatility for bigger wins, while low volatility slots provide more frequent, smaller payouts. Always check the RTP and game reviews to maximize your chances of winning while enjoying the thrill of online gaming.