These following cryptocurrencies are predicted to be some of the promising one's and could follow or surpass Bitcoins expectations.
Ethereum - It is a smart contract based platform. Much different than Bitcoin.
NEO - Also a smart contract based platform. Called the Ethereum of China. Has the same potential if not more than Ethereum.
IOTA - Truly revolutionary blockchain technology. Transforming blockchain to a new level essentially. It’s actually Tangle technology, not blockchain.
Civic- Building an identity based platform that could replace a lot of login credentials. Doctor’s office, airport, etc.
EOS - A new ICO that will bridge the gap between programmers, and the blockchain making it easier for them to program and develop on.
@yashhanda