For me, a Good ICO is the effectiveness of their product or projects and their consistency of their roadmaps.
Good ICOs have good community managers as well because the community especially on Telegram Channels and Reddit as both are most popular on crypto communities.
as I observed, most of the fail ICOs aren't having strong foundation of communities that's why ICOs have less active members and no community managers are more likely will be soon vanish or ended up being scam or fraud.