XRP is extremely quick. We also need to take into account the transaction volumes, as this can affect the speed of a single transaction. A lot of coins to tend to get slower due to congestion.
It's not extremely quick, DAG coins have a better perform rather than ripple with zero fees and instant transaction but the sad thing if that was a centralized system because server controlled by the developer.
Credits (CS) promises more than 1,000,000 transactions per second, with future scalability to 10,000,000 per second
The platform has an Alpha version, so we should wait more for actual results.
In credits alpha and it's still 200k TPS but i'm not sure about that. It seem we need more people to be used the alpha and test everything about that.