What is the most successful ICO ever?

Could you elaborate on what is considered the most successful Initial Coin Offering (ICO) to date? What criteria were used to determine its success? Was it the amount of funds raised, the number of participants, or perhaps the long-term value appreciation of the token? Did this ICO revolutionize the industry, introduce novel concepts, or simply execute an efficient fundraising model? I'm curious to understand the context and implications behind this remarkable achievement in the cryptocurrency and finance landscape.