I dont think ETH will surpass BTC. BTC has so called "first mover advantage", it has more use cases than just sitting and being "valuable" and for a while it will still be the first "safe" choice for newcomers to put your money in.
What comes to XRP, well i truly hope this centralized garbage will burn with a bright flame. Now, personal contempt aside, it just doesent make sense in this world. It offers almost nothing what the blockchain is meant to offer - XRP is just another regular database that is decorating itself with the idea of being innovative and decentralized solution. Banks would never adopt it if thats the case - too risky and giving away too much power!