Now many altcoins are at the bottom, so many have a chance to show great growth. You can select several of them.
I select Ethereum and Ripple because these two altcoins showing greatly in value than the others. These two alts are best for long term investment with great profit awaiting in the future. And promisingly these (ETH and XRP) altcoins also keep always closer to where bitcoin in positioned. So, it's demand will probably grow high in the cryptocurrency market.