XMR and XRP
monero the best!
XMR is a very good coin to invest, but personally I'm not much interested in investing in XRP as I think it's better to invest in ETH or LTC.
actually both altcoins are good if indeed you are sure of the coins because we don't know the future of the two coins how could these two coins have the potential to rise or even vice versa so we have to really be able to choose the best among the coins you mentioned