If you want to try a long term investment, you are better to analyze about what coins possibly to survive and continue to improve at future. Be careful in analyzing: the popularity of the coins, its platform, the valuable of the coins, and the potential improvement. With those consideration points, I suggest the coins that have listed on exchanges for the option. Bitcoin, ETH, Stellar, and XRP are good coins for a long term investment. You can choose all or one or two of the coins, it depends on how much you money.