A coin which is consider as a good coin is the coin that has many user.
you can see it on the market, if the volume is big, there is a chance that coin a good coin
It is really hard to tell which ICO are good especially there are lot of ICO and it will take your time to.check it one by one. You can check atleast 3 ICO that caught your attention . Then start to check the white paper and do background check of the developer or the people behind the project.