Bitcoin, Ethereum and Steem, those three have clearly bright future. BTC is the father of all cryptocurrencies, there is a cult that will persist anything. ETH is handy, swift and ready for mass use by the general publict. Low fees, fast transactions, not just a copy of BTC like LTC.

And finally, Steem. Steemit is on the way to slay Facebook (not in number of users alas, but it destroys FB in the economical matter since FB stocks loses their value and the investors will abandon FB) and rule the social network world. Hence Steem gains value.

Invest into those three if you can :)