I suggest you checkout ICObench. It's a site that collates reviews about ICOs and rates them too. They're pretty useful.
ICO ratings cannot be trusted because they can be payed to have a good review on their website. The best thing to do is to do your own research and don't be lazy because it is your investment.
Some web-pages, comparing ICOs are declaring that they are not providing paid ranking for ICOs. What do you think, are they trustworthy?
You are right in part. Some rating on icobench are deliberately overstated. Usually such projects are at the top of the list. But some estimates given by experts are correct. I usually choose one expert who likes to give low scores and adhere to his opinions