ICO rating websites provides us the summary of every good ICO based on their perspective. Though they cannot cover all since there are many projects launching almost every day so they may overlook some good projects. And we never know maybe they are paid to have a high rate on a certain project. But before I invest in a project, one thing that I do is to look in ICO rating websites to have an idea which they gave higher ratings. That gives me a lesser time to find good projects.