These ICO rating websites can only select the "good" ICOs and they won't give the best ones. Because sometimes these scam ICOs pay a nice money and get high-rated, also they can get some ads from these websites. So maybe they can't be the best in these rating websites but eventually, they will be in a high position. When I was investing to an ICO, I would find ICOs from popular rating websites. Then check their team, where they got the education, do they have a past. After this I check their social media posts, blog posts, GitHub commits. If everything looks okay, then it probably works but sometimes I ended up with %70-80 loss.