In my opinion, for long-term investment in cryptography, it is best to use altcoins, which cost less than one US dollar. These are interesting coins for earnings. Profit will be unexpected and pleasant.
There are many good coins in the market which are very promising for future. Ethereum, litecoin, Ripple, Monero, Torn, Liza and EOS are the top Altcoin and are good for investment. You should select any of these coins. Remember one thing, never invest in any anonymous coin otherwise you may be scammed and lose your money. It is much better to choose only authentic and reliable Altcoin for your investment.