You can research yourself because I think we do not have the right coin list that can be good to buy. That is because many coins have the same chance to be the potential coins that can increase. If we suggest you take a look at one or more coins, that will not always give you a chance to profit because we have a different reason to buy the coin. But if you want to hold it for a long time, you can buy bitcoin and hold it. The only bitcoin will give you the biggest profit than the altcoin.