Nothing beats doing your own research on the ICO's underlying business concept, its commercial potential and team behind it.
ICO ratings sites are generally well-intentioned paid-promotions but a useful place to find out about upcoming ICO's, in general.

My tip, if the ICO rating site has an "About Us" section and informs visitors of where their business in registered and who are the directors etc., then they are more trustworthy that "anonynmous" ICO promoters.

However, everyone, Caveat Emptor .. do as much research as you can on the ICO company.


* Caveat Emptor: the principle that the buyer alone is responsible for checking the quality and suitability of goods before a purchase is made.