I think the best altcoin will buy is coin that proven that still their even the market is bearish and also some projects that have good and unique products. Much better to make a deeply research before we buy to some altcoin so we know if that coin is great.
now it's very difficult to choose and determine the altcoin that we invest a lot of research and research and now the risk that will be obtained is enough your confidence and patience is an important capital in investing with altcoin