Both the good and the shit coin so much look alike, infact some of the shit coin looks more genuine that the real ones, to know those one that are worth investing in, trace the history of the manager and the team, how many project have they successfully managed, check the feasibility of attaining the hard cap, you can get more of this on the white paper.
I am not so good at determining which altcoin were worth investing in but i am doing my best to look for the best reason for a certain altcoin like technical analysis and white paper review of altcoin that can convinced me to invest in it. Up until now i am still favoured in ethereum for it was already proven its project ability but i am not set aside the other good altcoins like ripple and binance.