go with ethereum and bitcoin, this are on top when it comes to blockchain, ethereum is one of the most popular because there chain are being use by altcoins, as the foundation, also there are more coming updates for ethereum, and then the most popular one bitcoin! there is no more to say about it although some say that the price will go to zero but until now look at it, its the father of all coins for me, and all of the coins are being converted to bitcoin for cash, some are trying now to integrate altcoins the cash or any currency we are using but so far the more reliable is bitcoin in my point of view i know most will agree with me when it comes to that.