Both coins have great potential and are among the top cryptos in the market right now. Ripple is having a better market cap as of the moment.
XRP by Ripple is a centralized Crypto owned by a bunch of banks and has too much supply. Currently, it already has a huge pump. Even higher than ethereum.
ADA by the Cardano platform is a 3rd generation Crypto currently popular in Japan has a lot of room for growth. Expect that its price will surge once it sees major adoption.