What Makes A Good Alt Coin ?

There seems to be quite a few new crypto coins launching at the moment and obviously only a few will actually survive in the long run . So what would help to indentify a good currency to adopt or invest . Services and providers would need too accept it ,first and fore-most ,it would need to confirm fast and be easily broken down into smaller units are unless good qualities any future user would need to look out for .

So far  it seems like only  bitcoin has attempted to go mainstream by being accepted by many different types of services ,and has became a legitimate way to pay in many places (mainly following  FinCen regulations).