Single zero roulette (European and French) has only 37 numbers in total (1 less than double zero roulette, the American roulette), while the payout ratios remain the same, which indicates to us that the American roulette RTP is the worst to the player. European and French roulette have a higher RTP and therefore a lower house edge.
The European roulette RTP is 97.3%, while the American roulette RTP is only 94.74%. Therefore, it is easy to conclude that European roulette is much more player-friendly. If you have a choice, always play European (or French) roulette. However, if you are looking for the highest possible RTP, you should play roulette with Bitcoin in crypto casinos.
Besides that, there are no major differences between the games. The differences in single and double zero roulette bets exist due to the extra zero (00) in American roulette. There is a special bet called top line in American roulette, which covers the numbers 0, 00, 1, 2 and 3, while the bets called trio (0-1-2 or 0-2-3) and basket (0-1-2-3) are only available at European and French roulette tables.
In addition, French roulette is usually played with a La Partage rule, which modifies the RTP of some bets even further.